So far it appears that you can only change the speed limit and wheel size on a CAN BUS model using a $30 programing cable unless you really know your PC skills. At best, it's a hack to get into only some of the programming options, but it's not very straight forward.
The UART motor is completely programmable, you just need a USB to UART cable ($30) and the software which is relatively easy to find here: https://everyamp.com/bafang-ultra-m620-programming/