https://www.evike.com/products/101324/ CYMA Platinum Complete Version 3 Gearbox w/ High Speed Motor for AK Series Airsoft AEG Rifles

So I want to buy this gearbox to just drop into any rifle I print. I don't really know if its a good choice to get this one. I know the difference between the versions and types. I talked with some people and they mentioned its just easier to use a drop in gearbox instead of a from scratch one. I just want to make sure I can use this to work with any 3d printed shells I make so for example I can print and ar and drop into this (ofc with modifications since this is a v3 gearbox) and or i can drop into an AK without issues. Aswell as printing my own designed rifles.