I’ve not followed this thread, nor, obviously, the PMs, but I understand there is a plugin with a polling loop. What it’s polling, how often, and what protocol is unclear to me.
If it’s TCP-related (sockets / HTTP / …) then, if it’s not doing it already, this can be written with asynchronous I/O that doesn’t block the process. It’s true that openLuup is single-threaded, but if the processor is busy with other things, no matter how many threads you have, there will be delays.
I’m happy to try and advise if there’s a well-posed problem to solve.