M.2 would technically be the best performance available, but realistically I don’t think you’d notice the difference over a USB SSD. Maybe a few extra seconds on boot.

It’s unsettling to read comments that you know were typed with one hand

You should try begging for cash somewhere else

You can’t self host a tracker like that, at least not for free, because the only way for the data to be reported is through a cellular connection which costs money. The subscription fee seems perfectly reasonable