Common eBike problems and solutions

Hey everyone!

Been tinkering with my custom-built hardtail eMTB lately, mostly riding local trails and some urban commuting, probably 20-30 miles a week. I've had a few minor hiccups, like a loose motor mount bolt after a particularly bumpy ride, and once my display cable got snagged. It got me thinking: what are some common issues you custom builders run into, especially with aftermarket components or unique setups? And more importantly, what clever solutions have you found? I'm curious about everything from wiring woes to battery placement challenges or even just unexpected wear and tear.