Note: nothing against fluid.sh, I am struggling to figure out something to build.
I am now so deep into the rabbit hole that I have made a version that runs entirely in the browser and an ESP32 version. I have now also taken the printer apart to find that the built in BLE is an external module and I could interface directly with the printer by replacing it with my own custom PCB...
[1] https://sschueller.github.io/posts/making-a-label-printer-wo...