I’ve just started compiling qpkg’s for QNAP NAS devices (limited at present but will expand).
You will be able to run all three variants alongside each other (Stable/Milestone/SNAPSHOT) with ports/console mapped differently.
links for downloads and config: openhab-qnap/README at main · delid4ve/openhab-qnap · GitHub
Let me know anything not working / requested features etc