When you put an endorsement quote on your project page, you're addressing it to a large range of unrelated people who majoritarly won't even be users of your project (yet).

It's basically advertisement, we won't ever reach some universal conclusion on what any specific aspect of it means for your project, it's all in the eye of the beholder.

It's also all social norms, the maintainer doesn't get a choice on how it will be taken.

Accepting a PR from a racist is a very different thing to using a quote from a racist as advertising for your product.

If you don't want reactions to your advertising, don't advertise.

I would be very mindful about advertising endorsements from anyone at all myself.