yesterday i tried to connect the Simple BCG GUI to my Beholder DS1 but the GUI was posting "GUI vs board version mismatch". I tried several versions but without success. It´s supposed to have GUI version 2.55 b7 board installed but not working. An advise would be to not mess with the PID settings because in general the DS1 is working good, it´s factory settings are good and you got the possibility to change to P3 (by tapping the board switch 3 times) wich is designed for lighter cams but i still got some micro oscillations wich i want to get rid of. Most important fact is that you have to set the cam up proper and you have to do correct balancing in order to have best results but i think a little bit of tweaking will help to get rid of the oscillation.
you could try updating the firmware to a version that has a GUI version that is available, I had this issue, sometimes it asked if I wanted to download the correct simple BGC version and other times it didn't as I tried about three different firmware versions.