PEP 501 is unlikely to be accepted *as is*. But it’s still a good starting point.
OK, before starting a new project, it maybe makes sense to finish the first.
Why not reject PEP-501 officially? Maybe with a reason. Then we know what's wrong with it.
You'd have to ask its author. Most likely he'll just withdraw the PEP completely without telling you anything more.
In short, I don't think you're going to get much out of trying to get anyone to say anything "official" about PEP 501.
If you really want to know more, you could probably dig up the discussions around that PEP and learn from that.
After that is done, we can think about a new start.
There's no need to wait for that.
What do you think?
I personally really would like to avoid the dollar sign which gets used in JS template literals.
Well of course. The Python equivalent would use the exact same interpolation syntax as f-strings (and before it, str.format()).