I use an AppleTV 4K on every TV. Media is on a NAS (TrueNAS Mini). I use a Kodi port called MrMC (~7USD in App store) to mount the NAS shares and play all the media (supports NFS and SMB). Run a container (on the NAS) with MySQL that MrMC talks to that syncs status between all instances. Works great. Watch in one room, pause and pick up where I left off in the next room.

https://mrmc.tv/