I got a real deja vu feeling about this but last time I didn't file the Enhancement report. Weird.
I just posted an enhancement report, let's see what happens.
Cheers
Don't expect much to happen. Enhancement reports are usually filed away somewhere and typically only get attention if they get duplicated many times (as in, many people want some feature). At least they know someone wants it, though.
The idea behind UIKit that the engineers keep pushing is making it such that common things are easy and all things are "possible with some work." Usually, enhancement reports that focus on something not currently possible with the given tools (and something not actively excluded by Apple) are given priority so that people can actually accomplish what they're trying to do.
As what you're asking for here is certainly very possible with the tools available to you now, I wouldn't expect much response. They don't like to burden the frameworks with little things that wouldn't be used much and only satisfy a niche. You're better off implementing the pins yourself.