While it is industry standard to ask for developers to turn over their work to their employer, I dont.

Im not you. Im a high dollar consultant capable of building systems of systems, Im not a designer, Im an occasional architect who helps out dev teams.

However, my code will never belong to the client even in their git repo, because the client(s) is(are) heavily outsourced and will share my code with (offshore?) (vendors?) who will claim it for (themselves?), share it with their other (clients?) for profit, and are in effect "mining me", to level up their offshore or otherwise outsourced business(es?).

This is illegal at the base of it and why it has so much support. Like dealing drugs in states which have legalized it or ignored it.

Im not on drugs. I also dont deal drugs. But my clients want to own my code, and yours, I suggest you say yes (usage) no (distrubution) and license it to them regardless of the wage you are paid. Otherwise you are just crib notes for a thousand unseen vendors vying to steal food out of your childrens mouth.

Good luck