The stream doesn't have a big advantage compared to the Polish bookie that you had open on the right. It is certainly not 4-6 seconds faster than the entries of the bookie.
Is the delay always the same, no matter what match is on? To run the streams, do you need to login to a site, platform that holds all streams for the tournament or is it the same link for all matches.

What about other tables and courts? A tennis tournament is usually played on 2+ courts. Are their streams for each court? Any advanced features like modifying the buffer length/speed?

Can you make a video of a tennis match running alongside your stream where the bet365 match center shows the entries of the points?