Increasing the maximum player count would require at the very least these changes:
- Increase size of clients list in the engine
- Change engine code to send indices with more bits (client & server)
- Change every line of code that references the maximum player count (patching code at runtime, client & server)
- Redesign code that abuses the fact that the maximum player count is 32 to store booleans in integer (https://github.com/ValveSoftware/hal...ggers.cpp#L947)
So it's not possible with existing games & mods because you'd need to modify the code. Even if you could do it, you'd need to disable VAC so it would be a cheater's heaven, especially since there's already memory patching going on so adding your own cheats in would be a lot easier.