I'm actually wishing for a switch to 3-4 with a 2 high shell like Fangio runs which seems kind of likely given Moore's past work with Brandon Staley and Vic Fangio. And I actually think we mostly have the guys for a 3-4 with a 2 high shell other than the OLBs/Edges and the 0 Tech NT but we lack those for a 4-3 to and I think it's easier to find a NT in later round and OLBs for a 3-4 in the draft. Also 2 high safeties and match up zone CBs are easier to find.
My proposed 3-4 base is Breese and Jordan at DE, Ridgeway at NT (for now) with Granderson and Foskey (for now) at OLB and Demario and Werner at ILB (for now). you can also work in chase young at OLB if he stays. Not sure Foskey is the guy you want starting, but he should be better as a 3-4 OLB than he was as a 4-3 DE and if not we move on.
But like you said, we pretty much so need to rebuild the defense so we have a long way to go either way. So, if we are going to make the change, now is a good time to do it. And I think there are a lot of smaller edges in college that can play OLB in a 3-4 but lack the size to play DE in a 4-3. That should allow for good value on those guys in the draft with added speed on the field.