@Festivejelly currently the G17/G18/G19 commands wait for all queued motion to stop before they are executed. So if they occur frequently in your file, that could cause the movement to be jerky. Your first file does have a G19 command just before each G2 or G3 command, so I think that explains it.

I think the reason why RRF waits for movement to stop before executing these commands is so that if power failure occurs, RRF is able to write a G17/18/19 command that is correct for the movement commands that will be executed if the job is resurrected. So I can't unconditionally remove that call to wait for motion to stop. However, I could remove that call in the case where the selected plane is not changed, which should help with your example.