french fellow here 😉

« Peut-être qu’il ne l’a jamais été. » is the correct way. As strange as it could be (even for me), the pronoun refers to être and not to a.

May I give you a little modification on your first sentence ?

« Je crois qu‘un profond dégoût pour ma personne n’a plus lieu d’être. » -> I deleted propre because it was redundant with me ma. Your sentence was still correct and would be quite be accepted but it is a style fault.

I hope I helped you.