I kept at it and the 8bitdo SN30 Pro is finally working on my C64. The controller has to be in Android mode (B+start) and should be turned on before plugging in the cable. I found that in Windows mode (X+start) the Tom adapter would freeze but I didn’t notice so all my testing earlier today was made harder by that.
First game I tried was Doc Cosmos but now I want to give Gianna Sisters a spin. 🙂