I’m not looped into any possible home attempts to make DIY casings, but I would presume you’d need to do some problem solving with the material. It just seems like the most plausible angle to work on to me. The point of thermal issues is relevant, not just in the material standing up to heat but also for cooling the gun itself. It’s imagine that successful DIY printed casing would be more feasible with single shot or bolt action type firearms.

With traditional home reloading, no people normally don’t produce their own casings. You can buy them, or you can reuse already fired casings.