Thanks for the quick fix on the docs, certainly clears up some confusion I had, haha.
Regex would be very appreciated and powerful. I am also facing a need to validate statuses though, so I wonder if there's a way for a regex to apply to that field as well. It would be a little more abstract than than naming validation I guess, but I could see it still working. That may be out of scope though, if the discussion here is determined to be focused purely on validating text fields or something.
The way that old validate function worked seems to be the right idea implementation-wise. I understand if the new API ruled out that type of event interception though. Overall the need seems to be having the chance to validate an event before it actually happens. That's the common thread with all of these issues - the fact that currently ANY validation needs to be the product of detecting a change and reverting it, as well as completely custom logic, is quite daunting and taking up a decent amount of my development time.
I'm not familiar enough with the API yet to be thinking about performance, but I'm sure that would increase too when we aren't reverting so many changes.