So i take it that the conductors already pulled and cut, preventing you from going all the way down that adjacent section to the bottom horizontal wire way and back up in the vertical wire way of the section housing the feeder?
As to asking Rockwell, I doubt they will give you a definitive answer either. This is not specifically addressed anywhere. But I recall having seen somewhere in the NEC where they discuss junction boxes and how any splice made in a conductor must be in a junction box with a screw cover or a lock, that two of the exceptions to this were a motor controller and a Motor Control Center. Most likely when that was added someone was thinking of the wire ways in an MCC, but I don’t think it was that specific. So I think it’s likely OK, but as I said, I would add a lock and a warning sign.