Unfortunately, there is not much to change to speed that up as far as I know. Maybe this will help you in any way.
You could cancel rebuilding if you want as it adds .cpp and .h files and then starts to rebuild. Also, you could disable compiling when adding a new C++ class by going Edit → Editor preferences → Miscellaneous → Hot reload → Automatically compile newly added C++ classes.
A hardware upgrade is always welcome or you could install Incredibuild, I have it and it could accelerate compilation time much and Unreal Engine uses it automatically without the need for additional setup. You could always try it and see it for yourself if it’s a good fit for you. Hope it helps 