I think it would be nice if, in a time travel AU, S1 Jon’s acidic bluntness made S5 Jon realise how poorly his Martin is treating him. Something about how suffering doesn’t necessarily make us better and in Jon’s case it left him desperate enough to be forgiven for existing that he’ll take anything from someone willing to say “I love you”. His past self making him realise things instead of the other way around. Not all change is for the better.