I hinted at it a couple of times, but now my LibreOffice frontend for OpenNMT has a homepage and all: https://lernapparat.de/libreoffice-translate/
There is a Windows OXT (extension package) including all dependencies and a cross-platform one that requires you to install the dependencies yourself.
I’d be very happy if this was useful to anyone and if you need help with getting your translation model to run in LibreOffice, I’ll be glad to assist.
Between the two talks that have slides and video linked on the page, the one at Hacking Machine Learning is probably from a perspective that is closer to you here (i.e. you have the model and add the LibreOffice part).