[jareklupinski]

> I would be interested to better understand how synchronization is achieved here.

not OP, but worked on similar large displays stitched together using multiple servers with their own GPUs

for most applications, TouchDesigner running on each server was used to arrange media on screens connected to that server as a single group, and software Sync (https://derivative.ca/UserGuide/Sync) kept media playing across different groups within a frame or two at worst. for stricter (higher budget) installations, the GPUs were chosen to have native hardware framelock-type features, but you can connect a surprising amount of displays to a single machine if you get the right server motherboard (digital signage is a big customer of those kinds of rigs)

syncing the audio with the room speakers was a completely different story