Hi
This works for me. I put my tc ditto x4 looper in a stereo fx loop at the end of my Helix signal chain. If I am switching presets I make sure it is in the same place on that preset. If I change sounds the recorded loop stays the same.
I run the Helix out to a small mixer, I also run the output of my beatbuddy drum pedal to the mixer. It is clock synced to the ditto looper. Hours of fun.
https://youtu.be/u9Lb5Ua6P_I