I just did rapport quest that needs certain amount of virtue point higher than what I currently have. There was a conversation with the Mayhem Legion clown that needs 420 virtue point (my highest is 344 on courage) and I can click the response without a problem. I tried doing it on succeeding quest response and it works too. It is supposed to tell you “you don’t have enough [virtue point]” like when I tried to accept the quest from metus island when I didn’t have enough courage.