I've found so far that the higher the scope is off the bore, the more adjustments you're gonna use up if you can't shim the mount to point lower. I found that out from mounting optics on SMLE rifles. As for being inherently less accurate I can't tell.
Practical accuracy takes a hit because of ergonomics. Your cheek mount will be a chin mount and its consistency will suck.
If talking purely accuracy, mounting a scope higher will not effect the accuracy of the rifle. It will put the scope a bit more off centerline from the bore and require adjusting more in order to zero at closer ranges, but thats about all. The cheek weld point made by muzzle is a very good one also.