The included rack ear mounts was not compatible when using the RAIL-B02 rail mounting kit, so I’ve contacted QNAP and they sent me these as a replacement.
Handles are based on the TS-459U/419U/410U rack, these make it much easier to pull the switch.
Lots of clearance from the mounting rail, compared to the included one.
While the rack ear is not black like the old one, it does actually fit which is more important.