I know the recommendation from both Sram and Shimano is 1-3mm for outer FD plate above the big chainring teeth, but do you think running it more like right at 1mm is going to keep the chain on better than 3mm above?

Basically, crazy choppy sections of trail that I hit at speed and I'm in the big ring, the chain comes off too frequently. I'm thinking the adjustment I need to make is lowering the FD so that it is probably right at that 1mm of clearance. Its a high direct mount FD. Limits are set up good and cable tension is right where it should be at. No angle adjustments are possible with this direct mount style, but height can be adjusted.