That’s an artifact from the J-Tech plugin generated code that I intentionally replicated. I’m finding that without it the LCD display gets out of sync with the Octoprint stream/machine motion making it useless for all practical purposes. Further testing is indicated. Not sure of the original intent, all it seems to do with my rig is make an unsightly defect when the delay is more than zero.
Ran the full test code this morning. Marlin does seem to tolerate G00 vs G0 and the result was very promising.
I’m on Github so I’ll probably fork or branch at some point after I decide how far I want to go with this. No problem sharing the interim plugin code if you’re interested.