Hey.
I did a somewhat stress test with your mod and installed the Infinite Quality Tiers Plus (https://mods.factorio.com/mod/infinite-quality-tiers-plus?from=search) mod and it just went up to uncommon 3. I expected it to go all the up to the very last quality tier (which there are 255 in total).

There was a limitation 32 quality levels to avoid infinite loops in case a buggy mod messed up with quality hierarchy,
The mod is now verifying that the hierarchy is valid and there is no infinite loop,

Hope you enjoy :D
You can now spend 1 year upcycling those assemblers to that phenomenal quality:

https://imgur.com/a/Ff1sbNb

Fun Fact: The game crashed when I first tested, that required a 2nd round of optimizations in the layout algorithm.

oh wow, thanks. that was quick