Hi Lostra,
This shouldn’t be too hard to setup in your menu system to enable/disable console commands that can execute.
For instance, if you wanted to disable distance field shadowing you would use the console command r.DistanceFieldShadowing 0 in a Execute Console Command Node in your blueprint.
For DFAO you would use r.DistanceFieldAO 0 will disable the feature.
There have recently been significant improvements for DFAO to improve performance on mid range machines.
I hope this helps.