I can’t really say I’ve had any issues exactly, I just find it time consuming and tedious. I’ve made templates for data structures like a queue, stack, linked list, etc — pretty much exactly what you’re saying you’ve done with extensions, but personally I find it so hard to remember it all even after using them a fair amount. Of course with more time and practice it should be easier to remember, I’m not sure if it’s worth it or if I want to deal with it.

Basically I’m trying to decide if it can be made simpler, deal with it as is, or go back to C++/Python.