eBike technology explained

Hey everyone!

Been lurking for a bit and finally decided to jump in. I'm deep into planning a custom eMTB build for some serious trail riding – think steep climbs and technical descents, aiming for about 30-40 miles per charge. I'm really trying to wrap my head around the nuances of different motor technologies, especially between mid-drives like Bafang or TSDZ2 and how they integrate with torque sensors vs. cadence sensors. For those of you who've done custom builds, what's been your experience with specific motor/sensor combos, and what do you wish you knew about the tech before you started? Trying to make sure I get this right the first time!