It’s not released yet, but I’ve been keeping my eye on the Open Printer project by Open Tools. You can sign up to get email updates on their Crowd Supply page.

Edit: Sorry, just seeing the no Wifi/Bluetooth, so this might not be the best fit (but it does aim to be fully open source, so maybe in the spirit of what you’re looking for?)

Thank you! Just to make sure I am following correctly, for your LXC running PBS, it sounds like you used a privileged container on Proxmox itself, right (vs. an LXC on TrueNAS)?