First my apology for not having the detail information - my schedule is crazy right now - but this may be of use -
Before I entered the roll length - I used the roll with No length entered (and I do not remember how things were set up but I was not asked and did not supply a length at first use). That way when I switched to cassette or other feeder it just backed out the roll with NO barcode!! Meaning it can be done, we - you just need to poke around a bit. I know for when this worked for me, it was when I did not have a length of roll entered, so there is a way to not have that entered in the menu somewhere, I will start there when I revisit this. Good luck.
When you eject the paper it prints the bar code on the roll, or course. I was disappointed the first time I loaded the roll paper back in, that it did not trim off the bar code before the first print. I looked to see if there was something under Media Detail Setting in the menu. The closest I found is Trim Edge First (Forced/No Cutting) [Whether to trim the roll for to make a smooth edge before printing], but that's not quite it.
Has anyone found a way to get the printer to slice off the bar code?