Effectivethesis.com contains many possible topics
There’s also Jacy Reese’s 2018 list of half-baked volunteer research ideas
There are some research ideas at the end of EA Summit’s list
Global Priorities Institute’s research agenda a has very many possible research projects listed.
80,000 hours as a list of potentially promising paths that they haven’t written reviews on yet. I vaguely remember them mentioning somewhere that it could be valuable for people to write reviews about careers they are seriously considering. I guess 80,000 hours framework could be used for that.