Premiere Pro creates porxy files from the project window, but it does it extremely slow. It seems to work sometimes, at about two clips per second exporting to ME. But most of the time it takes about 30 seconds or more to export just one proxy clip to media encoder.
I've build a new sytem based on alderlaker, ddr 5 and windows 11.
The irregularity in this is what seems odd/to be a bug.