Strongly, generally, although I also try to see who they are today versus who they might have been. It also depends on what they are saying and less on what somebody tells me they believe. For example, if someone doesn’t understand or is uncomfortable with a trans person but at the same time believes everybody should have the rights and ability to live life as they choose (basic tolerance, essentially), I don’t consider that transphobic specifically. Some people would though.
I avoid altogether, look for alternatives, or do my best not to support them financially at least. So I avoid anything written by Lunduke, I don’t avoid all of JKR because I like the franchise, but I get anything secondhand.