Regarding this operator proposal, I also think we can still do this comfortably with the existing Python syntax. The problem that I have is I don't really understand what the problem is that you're trying to solve. It would be helpful if you had some explanation on that front. I see there was some discussion, but it's now buried in the email chain.
Here's some example "custom" assignments. Note that you could substitute the Ellipsis used here for any unique object, e.g. one that you could import from your HDL library.
It's already been said a fair amount, but my personal opinion on adding more operators is that they can reduce the complexity of individual programs, but it comes at a wider cost of the language complexity. That is; you can "simplify" a book by taking chunks of text and associating them with a custom key, but you now need to remember the codex in order to read the book.