Glad to discuss this a bit more in detail below:
1. Game stuttering probably doesn’t originate from difference in frame rate. Probably it rather comes from game and spacedesk encoding competing for CPU resources.
2. Framerate cannot easily be increased because spacedesk is using CPU encoding for each frame (this applies to both USB and network connection). CPU load would increase and even latency might increase since encoding would possibly take more time.
3. Hardware encoding by spacedesk would be prerequisite for increasing the framerate. Even without increasing the frame rate it might be the solution for the above named problem. Even at the existing frarate the stuttering might decrease if the game has enough CPU resources available (not taken away by spacedesk CPU encoding any more).
Now the big question: When will spacedesk support hardware encoding?
The answer: No specific scheduly yet…