Framerate limiter does not operate as intended

[Kay-STL]

Describe the bug
The framerate limiter (MaxFps global property) does not operate as intended.
The check, which occurs here, simply runs Task.Delay for the equivalent TimeSpan of the MaxFps setting (TimeSpan.FromSeconds(1/MaxFps)).

This results in the actual framerate being much lower than the limit - with the default MaxFps = 65, I observe around 40-45 FPS max, despite the device having far more perf headroom.

To Reproduce
Steps to reproduce the behavior:

1. Set MaxFps to 60
2. Enable ShowFPS
3. Observe the actual framerate is much lower than 60

Expected behavior
The draw loop should be checking the time elapsed between draws and returning before any work occurs if it isn't greater than or equal to the MaxFps TimeSpan, rather than delaying the task.