Allow to set background FPS like we had with beta's MainLoop

[TremensS]

@joreg

so not really sure where this drop comes from. i do remember in the past there used to be a windows setting to generally degrade apps that don’t have the focus. wondering if this still exists and such could be the reason?

Mmm that’s an interesting lead to investigate!
Will try to dig the subject and report.

If you have any ideas in the meantime…