Hi, i found two options for this:
1) "offset" option in the LEN(gth) menu. "hold ALT while turning the encoder to change the offset of the starting stage. " - i found this not as useful to set offset in LEN menu but instead modulating the offset via CV-in or Modlane.
2)"Skip" function also works, skip the stages until the one you want to start from and then "You can quickly swap which steps are skipped and which are un-skipped if you assign
“Skip Invert” as the destination of a CTRL knob, AUX Input (X, Y or Z) input or a MOD Lane."