I do not know of any code requirements for non metallic raceways to need protection thru sheetmetal. I was hit on pulling ENT thru metal stud w/o bushings once. I asked the inspector for a code section, he called his boss and asked "does ENT require bushings thru metal stud?", got a "no", and wiped that 'violation'. I would guess similar rules exist for LFNMC.
I have to wonder if the vibration by the generator's running wouldnt eventually rub a hole thru that and short out the wiring inside.
