I’ve been messing around with GLua for a good few years now and have never found the need to use coroutines. A lot of people probably don’t even know what they are, seeing as they’re used close to no-where.
Lua coroutines are like Threads, though they don’t run concurrently, they run collaboratively. So if one of them freezes up, so does your game.
I don’t know about other people but one of my main uses of threads in other languages such as C# and Java is stop certain blocks of code slowing down or freezing up the main Thread. This functionality isn’t achievable in Gmod and it would be hella useful if it was. I’m pretty sure Computercraft, a mod for Minecraft runs coroutines concurrently. If it does, running coroutines concurrently on GMod’s implementation of the Lua 5.1 engine isn’t out of reach.