Are you an advocate only for +=. or for similar operators for all
As someone who's implemented and used `..=`, my 2 cents would be that adding it to the language is actually unwise. If you're going to create a large string through repeated concatenations, you should almost certainly be using some kind of pattern that leverages table.concat(). It's far more efficient because it avoids the allocation of intermediate strings. `..=` just creates the temptation to build long strings in a way that wastes a lot of memory and processing time. I'm still cleaning up ancient parts of my own codebase where I used `..=` when I should have used table.concat().
Arithmetic compound assignment ops are nice to have, but, the generalization to a compound assignment for all binary ops is a bad idea, imo.