In general, for donating to alignment work, I think that the best approach is to focus on local grants, because those are the ones that won't be picked up by bigger funders, who have a lot of money right now. By "local" I mean things like: if you meet someone who seems promising, fund their flights to visit an alignment hub; or fund them buying textbooks, getting tutoring in ML; etc.
My guess is that the Long-Term Future Fund is the best you can do. (I'm a fund manager on a different EA fund.)
Larks' 2021 AI Alignment Literature Review and Charity Comparison is a good summary of the organizations and their funding situations.
I don't understand this field well, I'm hoping you guys can help me out.