Hi, I just bought 2 weeks ago "MIDI Captain STD" with 10 switches by Paintaudio, it's not expensive and it's a good extension for me.
A new Firmware 3.5 is for the PLAYER, but you can program it to your taste! And I wrote that a new Firmware with more options for the PLAYER is planned!!
More information: https://paintaudio.com/
I bought it at Amazon.de:
Search for: PAINTAUDIO-Multi-Effects-Synthesizer-Musiksoftware
There's a version with or without wireless function.