I might be stretching the use of LibreElec, but my HTPC is used as a Docker host as well as media machine for Kodi.
And to split the work a bit between my NUC and some other machine (Pi4 with external storage), I'm running Docker Swarm. It's all fine with the Docker add-on.
But one major issue is that it's not possible to run this way, since the kernel used doesn't seem to have VXLAN support enabled, at least that's my conclusion from the errors I'm getting when trying to start services in the Docker swarm. This is especially a problem if you run reverse proxy for services on either Swarm node, since you can only run one proxy that should be able to reach multiple services on multiple hosts.
I found on the forum that this had been request before, but it wasn't a long thread since I don't think it was explained why this is needed.
So in short: if you want to run some Docker containers on the LibreElec machine, this works great. If you want to create a Swarm with some other machines and create reachability among them (for example for reverse proxy etc), then it's a problem due to the lack of VXLAN support in the kernel.
Thanks