reWASD

https://rewasd.com
Focused on remapping USB and Bluetooth devices to Windows exclusively
Software-only solution, no support out to any other devices
Proprietary, closed-source, 7-day trial, Windows only
No emphasis on helping users with disabilities
Hosts unrestricted downloads of .rewasd XML files for configuration remapping
Hosts some configs that only appear to be useful for cheating

reWASD by the creators of DAEMON Tools is a polished looking app for remapping modern USB and Bluetooth gaming controllers to mouse and keyboard Windows PC games while also allowing for additional features typically only used for cheating purposes. This remapper appears to be the most well-supported app in active support or otherwise. Their lack of a hardware product means they're selling the software for, in essence, ~$26-$42 USD and locking users into a license agreement. There is no consideration around supporting users with disabilities in any way as far as I could see. One competitive note: the .rewasd files are raw XML in a format that appears to be very easy to parse and it would be possible to incorporate an import tool should one be useful.