Dude .... I think the big motor sound & prop wash are more detrimental to the situation than the depth of water your DI ping is running in.
I've gone over cover in less than 10fow with my DI & not noticed any problem, and now I've experienced & personally done the same thing with a DI & Livescope numerous times without spooking the fish.
I do, however, know of instances on this one local lake (where the water is consistently clearer than the other lakes I fish) where there are times when you can't get closer than 20-25ft of a school ... regardless of what electronics you have running ... or they simply move off or scatter. That's been experienced firsthand by a couple of guys I know that have Livescope. Now, as to whether it's the ping of the units, the trolling motor noise, the presence of the boat, or other things ... it could be any of them or all of them, but does seem to occur more often when the waters are on the more clearer side.