Thanks for this. I've tried the nuclear option, and strangely, for just a few seconds, I saw "Upload LittleFS..." in the command list, and then no more. I've no idea why that is. My EPS32 boards are recognised as such by the IDE, I can upload sketches and they work great on ESP32-C3, C6, S3 by xiao and waveshare.
I've now also tried a variety of older versions of the LittleFS plugin going back to the version stated in the article, and a variety of newer ones, all with full MacOS restarts in between. Baffling, and very frustrating! Why did I see it listed in the command list for a few moments I wonder? That must be a clue - not that it means anything to me unfortunately.