I disagree with your implied claim that terminal values are independent of understandings. I can’t think of any human values that don’t presuppose some facts.
Edit: also see this comment by scientism.
If I enjoy the subjective experience of thinking about something, I can’t think of any conceivable fact that would invalidate that.
Touché. (At least for an instantaneous “I” and instantaneous enjoyment.) Still, there are many terminal values that do presuppose facts.