I have created and I am maintaining the Printing Stack Snap from OpenPrinting:
This snap provides the complete CUPS-based printing stack for snap-based systems. It even automatically sets up driverless IPP printers in the network (most modern network printers: AirPrint, IPP Everywhere, Mopria Wi-Fi Direct).
Driverless printing works also via USB using the IPP-over-USB feature and all what one needs to do is installing ippusbxd because this makes the USB connection trigger the ippusbxd daemon via UDEV and the daemon emulates a driverless IPP network printer, making the Printing Stack Snap setting up a print queue automatically.
The ippusbxd project is also an OpenPrinting project maintained by me:
For getting this feature into the snap world, I will need to snap this (or add it to the Printing Stack Snap).
What this package does is using a UDEV rule file to start ippusbxd as a systemd service (you cannot start a daemon directly from a UDEV rule as it will get killed after a short time). As the daemon needs to get started for each connected USB printer individually the daemon instances are assigned to the USB bus and device IDs of the printers. Therefore we use a systemd template here.
See the UDEV rules and systemd files here.
Unfortunately, this is not yet supported by snapd and therefore this is my feature request.
By the way, this will also be needed by the future concept of printer drivers, the Printer Applications: