Another aspect of where I'm coming from is that there should be a high standard of proof for claiming that something is an important technical problem in future AI development because it seems so hard to predict what will and won't be relevant for distant future technologies.

I disagree. I would go in the other direction: if it seems relatively plausible that something is relevant, then I'm happy to have someone working on it. This is why I am happy to have MIRI work on this and related problems (to the extent that I even attended one of the Lob workshops), even if I do not personally think they are likely to be relevant.

ETA: My main reason for believing this is that, among scientific fields, willingness to entertain such research programs seems to correlate with the overall health of the field.