I don't even get why Alison the character even likes current Ian. Alison is so driven and motivated as an individual, what does she sees from current Ian.
He's a 26 years old intern that is still a loser. Sure there is "potential" for him to be a successful author, but as it is, he's just Perry without depression (and better physique).
For the record, nothing wrong with Ian per se, but I can't fathom someone with a drive to success like Alison to be so very head over heels for Ian. If Alison's feeling to Ian is more casual fling, like Emma, like if the dynamic is flipped, Emma being the one to "give anything to Ian", I think that would make a more believable story.
Emma is an idealist that's trying to bring change to the local neighborhood, Ian wants to pursuit writing as a passion, it makes more sense if Emma is head over heels to Ian than Alison imo.