And if we are in a world where these strange considerations do importantly affect what we ought to do, then it seems particularly hazardous to entertain philosophically unwarranted positions for psychological comfort .

I find myself confused by this sentence. If the strange considerations affect what we ought to do, why are they unwarranted? Or do you mean that considering them will lead us to change what we think we ought to do, but the change will be unwarranted because so were the considerations?

(And just to make sure I'm following you, are the considerations we are talking about in this paragraph those related to the question of whether reality depends on preferences?)