Done and done. I mostly ride a mt. bike off-road, and don't ride my road bike in highly trafficked areas, and never with those big groups of lycra clad butt sniffers.
I have no respect for the latter folk, holding up lines of cars they way they do.
I’ve lost far more skin MTBing than road riding. If you’re not crashing now and again, you’re not riding fast enough. Either that or your trails are too tame.
Plus, it’s more efficient to do aerobic training on the road, even if you’re an MTBer. MTB pros tend to do 70-80% of their training on the road.