Third Party Mirror networking and heavy games/high graphics

Hello all, I'm a beginner in networking and currently favour Mirror, as it seems it can do it all, even works with Steam.
My question is, how well it would handle a heavy/high graphics game, would there be extra latency or other issues, what to be careful about as a beginner in networking building a heavy game or other tips? You might ask what kind of heavy game, lets say for example RDR2 or Witcher 3 multiplayer. Both consume considerable GPU and CPU power. Thank you all.

 

Mirror does not care about graphics at all.
The game engine's renderer will be the limiting factor