I have a simular set up but in terms of kitchen printer it’s set up on pos2 and then a 10m usb cable to the kitchen.
I then added a new printer on pos1 and made it find the shared kitchen printer connected to pos2.
Then in my samba printer settings I chose that printer from pos1. It’s address is pos2\kprinter which I add to the path in samba.
Printer works from all 3 tills. Lovely jubbely.
Matt