I would estimate the time I spent for my living kidney donation to be much bigger than 52 hours as well. A lot of that is because I spent significant time ensuring that I was as protected as possible. Also because my donation was interrupted by COVID. 

First I would count my time in research to determine which hospital I wanted to go through as well as all my travel time to visit that hospital because it was out of state (my state has zero NKR affiliated hospitals and only did 6 living donor transplants last year - am I going to trust them to do mine? NO!) 

Next, I went through the process, was approved, then COVID hit. Enough time went by that I had to do the entire evaluation process over again. Each evaluation process easily took AT LEAST 52 hours for me because each time involved a two-day testing process plus travel plus additional local tests. 

Then time was wasted when my coordinator got COVID and couldn't put my case up for approval. Last minute extra tests - partially BECAUSE OF COVID - added to the time I spent doing this. 

Lastly, I spent extra time nearby the hospital after surgery in order to obey their recommendations that I stay local in case complications arise but also I did this to kickstart my recovery by eliminating my normal life responsibilities. It worked beautifully and I am recovering very well. But I know that if I hadn't taken that time off it likely would have impeded my recovery.

Some nuance here... First, every transplant center has different protocol in how they determine eligibility. There are some general basic requirements nearly all centers follow but beyond that there's a lot of variability. 

Second, NKR leads the world in donor protections. NKR-affiliated transplant centers have better outcomes all around. They tend to do better, more thorough donor screenings. You can evaluate transplant centers here: https://www.kidneytransplantcenters.org/

About GFR, most equations (whether they are creatinine based or cystatin-c) do in fact use age to adjust. And many centers will run both tests, as well as additional tests like a nuclear renal scan to determine kidney function, size, etc. There are no clear ways to determine the future but there are lots of tests that indicate whether someone is a high or low risk for future kidney disease.

Also regarding age, there is a good reason most centers prefer to take kidneys out of middle age people rather than young people: life habits are more strongly established and future health is easier to estimate because many of the most risky activities the person will engage in are in the past. 

Regarding the need/idea of "exceptional kidney function." Most humans living in societies with modern medicine do not need two kidneys; most can live just fine with partial function of one kidney. 

You are right to worry about future kidney health, particularly in the age of poor public health and pandemics. For instance, I believe there is a high likelihood that CKD will increase among donors who have caught COVID. And hospital-acquired COVID is not even reliably discussed in the data yet, so making a decision NOW about becoming a living kidney donor is definitely more of a gamble than it was pre-pandemic. 

Every transplant center has an evaluation team. It is never just an individual doctor who makes a decision about a candidate. This is good and bad in my opinion, but it speaks to your last point about incentives. 

Personally my experience felt like there were a lot of roadblocks to becoming a donor; they don't make it easy. Someone needs to be pretty motivated to even get to the point where the team makes a decision and by then you have had access to all of your test results so you can consult with other doctors if you wish. 

For the record, the screening process is not just looking at kidney health. It's also looking for cancers, heart health, etc. They are looking for anything that could make your surgery dangerous, anything that could harm your recipient, and anything that suggests longterm negative health consequences for you post-surgery. They have strong incentives to keep their rankings high with good outcomes and I believe those incentives outweigh any incentives you mentioned.

These free range animals are unlikely to fully subsist off the natural land. To feed them you need to buy or grow crops, which is another land use. It's very hard to make an EA argument in favor of humans eating higher on the food chain than is necessary. 

I think what may be missing from your analysis are different alternatives than the two you propose. For example, you've only considered using the land for free-range animals vs wild animals. You haven't considered using it for plant based protein sources to feed humans. You haven't considered using it as an animal sanctuary. And you haven't considered ways to reduce the harms/suffering that come to wild animals on this land. 

Nor have you considered the wider impact of expanding wild animals' habitats by gifting them this land. What is the larger impact of the existence of farmed animals on this land for wild animals in nearby habitats? 

And if they are raised and killed in these ways you deem "humane" then must their meat be used for humans? Is there a better use for it? For instance perhaps to feed wild carnivores? Or rescued carnivores? Is it really most efficient to use them to feed humans who have so many other choices?

I'm in the USA. We are the same blood type. For us, if possible (min weight and min iron levels met plus the other requirements), it is more efficient to do a "double red" donation. That is where we donate only our red blood cells. Our plasma is returned to us. It takes a little longer but is done less frequently. The recovery is a bit longer too, but regarding exercise it mostly just impacts your VO2Max, not your endurance or your strength. That's because you just have less Oxygen circulating, obviously, since you have fewer red blood cells. It takes about 2-4 weeks to rebuild those blood cells. Just want to share this possibility since it would reduce your travel time, your total donation time, and likely also your recovery time. Plus, it is the absolute most efficient use of OUR blood type. Cheers.

I'm a recent kidney donor and I want to clear up a few things. 

1-Dialysis and transplant are not interchangeable.  Transplant before ever needing dialysis is shown to have great improvement vs transplant after dialysis. The kidney lasts longer, the recipient lives longer. Living donors enable pre-emptive transplants.

2- Donor chains facilitated by nondirected or advanced donors enable the most hard to match recipients to get a kidney. They don't just shorten wait time. This is especially true if the donor goes through National Kidney Registry (USA only) which specializes in kidney transplant efficiency.

3- Standards vary dramatically between transplant centers and there are no universal donor protections.  NKR is changing that, leading the world in donor protections with rigorous evaluation and surgery protocols, as well as protections like short term disability insurance and the like.

4- Kidney transplant without the need for longterm immune suppressants is not longer a pipe dream, it has happened successfully. I suspect it will the new standard in a decade. Currently the way this is done is that the donor donates both an organ and stem cells. This will reduce/eliminate the need for replacement organs, reduce longterm costs, and extend the lives of recipients. 

5- Doing an advanced donation (aka voucher) allows the donor to list 5 people, which in turn enables the first of whom needs a transplant (and is healthy enough to receive one) to essentially 'skip the line,' providing direct benefit to a donor's loved ones. This is an excellent option when a potential recipient is a child and the donor is a middle age or senior person. The child may not need a kidney for many years, by which time the adult may not be able to donate. It's like an estate plan for your organs.

6- The pandemic has dramatically shortened the lifespan of people on dialysis, particularly those who cannot do their dialysis at home. Mortality rates in dialysis centers are incredibly high and will remain high so long as Covid continues to spread. The benefits of living donation to recipients now are far greater than they were in 2019.