I'm a Mommy so I'll answer.
No I would never wear diapers with my little. I have tried them and I don't like wearing diapers. I would only wear them if I had a medical reason that made it unavoidable. Though I do prefer my little to always be diapered.
Doing something obviously viewed as regressive is just not appealing to me as a Mommy.
I would never ever let my little sit in a messy diaper after I was aware they had messed their diaper. That is cause for rash and is unhygienic. I would immediately change them and clean it up. I feel like if I didn't change them immediately then I would be playing as an abuser of sorts and that makes me very unhappy to consider acting out.
Things that mimic abusive situations in real life are just not appealing to me.