I consider "reasonable use" to mean spending a small amount of money on offsets to purchase mental health in the form of not feeling guilty of small harms one might cause, where these offsets are not considered an EA activity, and one who considers themselves a part of EA would be spending more money, time, effort, whatever resource on something they chose for efficiency.

All advocacy for ethical offsets I have seen has been compatible with this reasonable use, and I don't think anyone is doing the unreasonable thing of calling ethical offsets an EA activity or focusing their EA efforts on them, or saying anyone should do that.

Jeff's article does not talk about ethical offsets. It says be careful about trading your happiness inefficiently for small gains in general utility, not anything about paying offsets instead.

I could cite sources (I can think of two more that are definitely online and not from private conversation). I am choosing not to because I'm not convinced it's a helpful exercise.

The fact that you don't think citing these sources is a helpful exercise is evidence that publicly arguing against them is also not a helpful exercise.

If you don't think people are interested in vegan offsetting, then why would telling them not to do it matter?

I think people are interested in reasonable offsetting, not offsetting as a primary activity. I think I have been clear about this.

I don't care very much specifically about vegan offsets. I care a lot about the general category EAs being able to do small sub-optimal things that enable to them to focus more on their more optimal efforts, and to sustain that focus long term.

The proportions are obviously very different in the EA community than outside it.

This is not at all obvious. All I hear about ethical offsets is at least EA adjacent.

I don't want to mention people because a) they may not want their views made public b) it might embarrass them to name them in a context where I'm being critical of their views, and c) in about 2/3 of the cases I remember the conversation was in person, so I can't easily cite the argument anyway.

Understanding all of this, I still say that it is net negative to publicly make your argument when there is nothing you can publicly cite as promoting what you argue against. If you notice such views in private communications, it may make sense to address them in those private communications.

I think that your argument is much more likely to discourage people making reasonable use of ethical offsets than anyone engaged in the problem you describe, mostly based of the proportion of such people that actually exist. As such, I think publishing such an argument without having the opposed view being actually promoted by anyone you care to mention is irresponsible.

I am not aware of EA associated people using ethical offsets beyond a small amount they don't consider part of their charity budget. Is there an "Ethical Offsetting is Great for EA" position you are arguing against?