Alright chad, from T8783 it seemed like Nuance was still far away, but 3 months doesn't sound that bad.
As suggested I commented on our use case for Nuance. I think we can probably stop annoying @epriestley with that Diff and I'll just patch it on my own installation while Nuance is still in development which is probably easier for all of us.

Coming from T12430: Stop cutting of Mail History for new Tasks I think Nuance could be a great Application for our Use Case of managing Requests to our Team.

Though I can't imagine a use case where keeping full mails for new objects makes anything worse than it is right now, I'll look into Nuance, which actually sounds nice, even though a bit overkill and far away in the stars for our use case. (and will probably bring the last of our Users who just learned to use Maniphest to finally resignate too ;-) ).