Wow, it's indeed flawlessly running on my Synology NAS!
I had to figure out how to setup that Macvlan thing but successfully followed these instructions:
http://tonylawrence.com/posts/unix/syno ... ogy-ports/
It describes how to create a docker compose file for pi hole (which I wanted to operate in my home network since years!) using a macvlan. This worked out instantly.
I then enhanced then yaml file by adding the tvmosaic setup using the same network that pihole is using. I attached the yaml file for your reference.
Thanks @DVBLogic for making TVMosaic available as Docker file!
I hope, that it will pass the long term test as well
P.S. I had to reset the license as well which now is indeed possible in the web license portal which is highly appreciated and worked instantly!!