It would be awesome if BTT had an integrated controller support for the Dualshock and/or Xbox Controller. A lot of steam games lack native controller support and while there are some apps that already do Controller Mapping, most of them are not very convenient to use. With BTT you could also have the possibility to assign the inputs to only work for a specific App/Game wich would be super useful.
I just started using Controlly, and I've mapped buttons on my controller to hyper+whatever. Then I map that keyboard shortcut to whatever action in BTT. Controlly can also map the analog sticks to mouse movements which is pretty nice.