I think with klipper is always on. I did wire it up to the pi and then klipper to send gpio commands to activate the servo. Seemed to work well for about three weeks but the started acting up. I rarely used the dual filament anyways so decided to go to the direct drive hot end. One day I want to get an enraged rabbit

I ended up switching back to the direct drive hot end. Too many problems with the servo dying

Sure I can share. I wonder if it would be best to share in the current klipper repo for the proforge 3 Also a couple things to note. Klipper cannot send the servo into negative angles. So I have set the servo so the angle = 0 activates the right extruder (Extruder1) and I found at angle=190 the left extruder will be used (Extruder). Also Cura seems to always inject the extruder code ahead of the "start gcode" So the printer needs to be homed before setting the offsets. I added a Safe home to check if the printer has been homed already. Its more of a workaround at this point. Come to think of it I should add a specific CURA T0 macro that calls Safe Home the T0. hmmmmmm Also still tweaking the configs. . https://github.com/WunderBertrand/Proforge3_Klipper