Dude, we aren't some desperate team trying to sell Hayward on how good the situation is. He's been here long enough to know what he's getting here. I think the billboards took care of the begging. If he's unhappy with the way things have gone, then he probably is already gone. I don't think that's the case.
I do believe he was considering leaving, depending on what other teams do/did in free agency. Lucky for us, Danny Ainge is busy shooting an episode of hoarders, where they find him locked up in a trailer, buried under a stack of newspapers and draft picks.
All we need is DL, and even then, I doubt any amount of word artistry is going to convince him our situation is better than he can already see for himself.