I had a similar idea for Asheron's Call, to build a modular plugin system for its bots. People could in theory be authorized to receive a plugin, which would be beamed from the server and dynamically injected at runtime. Reasonably secure copy-protection (aside from the rare determined and skilled hacker). I even had about 10k lines of code written, but it wasn't very impressive (although there were some interesting gems). Sadly, the game started getting DDOSed, which led to a sharp drop in population and abandonment of the project around 2014. The game shut down within a couple years after that.

I love the concept of making interesting bots for games that aren't originally intended for bots, but it's becoming harder and harder to do so given the issue of cheating. Makes for a major risk to a project that is already hard to justify doing. I believe Blizzard has sued someone for making and selling a game bot, so there is precedent for legal trouble as well, which is very unfortunate for hobbyists.