Evolution was working within tight computational efficiency limits (the human brain burns roughly 1/6 of our total calories), using a evolutionary algorithm rather than gradient descent training scheme which is significantly less efficient, and we're now running the human brain well outside it's training distribution (there were no condoms on the Savannah) — nevertheless, the human population is 8 billion and counting, and we dominate basically every terrestrial ecosystem on the planet. I think some people overplay how much inner alignment failure there is between human instincts and human genetic fitness.
So:
Some combination of:
Personally, I think the most impactful will be Regularization, then Interpretability.
My personal ranking of impact would be regularization, then AI control (at least for automated alignment schemes), with interpretability a distant 3rd or 4th at best.
I'm pretty certain that we will do a lot better than evolution, but whether that's good enough is an empirical question for us.
The Aisafety[.]info group has collated some very helpful maps of "who is doing what" in AI safety, including this recent spreadsheet account of technical alignment actors and their problem domains / approaches as of 2024 [they also have an AI policy map, on the off chance you would be interested in that].
I expect "who is working on inner alignment?" to be a highly contested category boundary, so I would encourage you not to take my word for it, and to look through the spreadsheet and probably the collation post yourself [the post contains possibly-clueful-for-your-purposes short descriptions of what each group is working on], and make your own call as to who does and doesn't [likely] meet your criteria.
But for my own part, it looks to me like the major actors currently working on inner alignment are the Alignment Research Center [ARC] and Orthogonal.
You probably can't beat reading old MIRI papers and the Arbital AI alignment page. It's "outdated", but it hasn't actually been definitively improved on.
What are the main proposals for solving the problem? Are there any posts/articles/papers specifically dedicated to addressing this issue?