Hi, I have a liyu SC-am serie and I am on antergos. i had some problem because all my computeur are on ttyACM and not in ttyUSB*.
So for inkcut work on ttyACM device you need to change this line in scanlinux.py in the folder serial:

def scan():
"""scan for available ports. return a list of device names."""
return glob.glob('/dev/ttyS*') + glob.glob('/dev/ttyUSB*')

by

def scan():
"""scan for available ports. return a list of device names."""
return glob.glob('/dev/ttyS*') + glob.glob('/dev/ttyACM*')

Like this you can choose your device in serial in inkcut

and for the countour cutting I found this->https://sourceforge.net/p/inkcut/feature-requests/4/

and when you would like move the jog you need to put the "contour cutting key" on and the plotter ask you would like move by the key or by the computeur. Say by the computeur and you can move the jog

enjoy!!!

Thanks for letting others know about your fix for this, johannahoj !