I do support C64 Mini/Maxi if you are using Carousel on your unit. You will need to modify this one line in the gameconttollersdb.txt file on your carousel drive:
Locate this line: 030000008f0e00001330000010010000,HuiJia SNES Controller,a:b2,b:b1,back:b8,dpdown:+a1,dpleft:-a0,dpright:+a0,dpup:-a1,leftshoulder:b6,rightshoulder:b7,start:b9,x:b3,y:b0,platform:Linux,
Change to: 030000008f0e00001330000001010000,HuiJia SNES Controller,righttrigger:b3,start:b5,x:b2,a:b4,leftx:a0,lefty:a1,righttrigger:b0,platform:Linux,
Let me know if you need any assistance.