I wrote briefly during and after the primary election about people on this forum who contributed fairly heavily to elect Carrick Flynn, a known entity in your community. Many of you contributed the maximum of $2900 to his campaign. He lost significantly to Andrea Salinas who brings powerful and progressive credentials to this race. Unfortunately, the contributions you made plus the many millions from the PAC funded by Bankman-Fried required Salinas supporters to dig deeply in their pockets to respond to a tsunami of ads, including untrue attacks.
Now Salinas is in a very tight general election race against Mike Erickson, a conservative Republican who has praised Trump. Erickson, a multimillionaire, is financing part of his election from his millions. Salinas, who has been in public service most of her life has no such option.
Building a financial base for a close race is made more difficult after a financially hard primary. In addition, Oregon has three swing Congressional seats in addition to a three way Governor's race and multiple close legislative races. There has rarely been as many demands for dollars and volunteers on the left as there are this election. The fate of much national legislation, including funding for science, pandemic research and mitigation, and climate change issues may hinge on whether or not Salinas wins and secures a Democratic majority. As one of the few new congressional districts in the nation, CD-6 is central to the future of much that EA adherents say that they value.
My ask: To the many hundreds of you who so readily supported Flynn in the primary, please consider supporting Andrea Salinas now. The choice of readers of this forum to fund Flynn in the primary plus the massive influx of money from PACs guided by EA principles made it more likely that she will lose this general election. If the Congress loses the Dem majority, if the chairs of committees that will make decisions about pandemic research and preparedness are all Republican, if the focus is on short term business success instead of long term sustainability of our world, we stand to lose so much. You can learn about this candidate and contribute here: https://www.andreasalinasfororegon.com
Cf. your update, I'd guess the second order case should rely on things being bad rather than looking bad. The second-order case in the OP looks pretty slim, and little better than the direct EV case: it is facially risible supporters of a losing candidate owe the winning candidate's campaign reparations for having the temerity to compete against them in the primary. The tone of this attempt to garner donations by talking down to these potential donors as if they were naughty children who should be ashamed of themselves for their political activity also doesn't help.
I'd guess strenuous primary contests within a party does harm the winning candidate's chances for the general (sort of like a much watered down version of third party candidates splitting the vote for D or R), but competitive primaries seem on balance neutral-to-good for political culture, thus competing in them when one has a fair chance of winning seems fair game.
It seems the key potential 'norm violation you owe us for' is the significant out-of-state fundraising. If this was in some sense a 'bug' in the political system, taking advantage of it would give Salinas and her supporters a legitimate beef (and would defray the potential hypocrisy of supporters of Salinas attacking Flynn in the primary for this yet subsequently hoping to solicit the same to benefit Salinas for the general - the latter is sought to 'balance off' the former). This looks colorable but dubious by my lights: not least, nationwide efforts for both parties typically funnel masses of out-of-state support to candidates in particular election races, and a principled distinction between the two isn't apparent to me.