Sure. To take one concrete example, I know this is an explicit belief of Scott Alexander's (author of SlateStarCodex/AstralCodexTen and major LessWrong contributor - these are the two largest specific sources of EA growth beyond generics like "blog" or 80k hours itself, per this breakdown, and were my own entry point into awareness of EA). This came out through a series of leaked emails which cite people like Steve Sailer (second link under "1. HBD is probably partially correct") in a general defense of neoreactionaries. Yes, these emails are old, but (a) he's made no effort to claim they're incorrect and (b) he's very recently defended people like Steve Hsu, who explicitly endorse HBD on the grounds that that is a valid theory that deserves space for advocacy. I also know Scott and his immediate associates personally, and their defenses of his views to me personally made no effort to pretend his views were otherwise.
When this fact came out, I was quite horrified and said as much. I assumed this would be a major shock. Instead, I was unable to find a single member of the Berkeley rationalist community who had a problem with it. I asked quite a few, and all of them (without exception) endorsed a position that I can roughly sum up as "well sure, the fact is that black people are/probably are genetically stupid, but we're not mean and just stating a fact so it's fine". This included at least one person involved heavily with planning EA Global events here in the Bay Area, and included every single person I know personally who has even the loosest affiliation with EA. To my knowledge, not one of these people has a problem with explicit endorsement of the belief that black people are genetically stupider than white people.
To be clear, I don't think that makes them insincere. I believe they believe what they're saying, and I believe that they are sincerely motivated to make the world better. That's why I was part of that community in the first place - the people involved are indeed very kind and pleasant in the day to day, to the point that this ugliness could hide for a long time. So I don't think stuff like "it seems like a bizarre thing for an EA to say" applies: I think they basically think that being effective requires facts and that 'scientific racism' is a fact or at least probable fact. There's nothing inconsistent about that set of beliefs, abhorrent though it is to me.