I just spent the last 20 minutes running Power O from I-Form Pro against the Packers 2-4-5 Cover 3 and changing which slide protection I did. I also ran it with HB Stretch From I-Form Pro against the Bears 4-3 Stack Cover 3 doing the same thing.
The Power O blocked regardless of slide protect the same for the vast majority of its snaps. You'd get a double team from the center and guard on the DT while the guard would pull around and as long as one of the OLBs didn't get a good push he'd attempt a block around the edge. The FB would basically do the same thing as the guard. There were a few snaps that had the double team fail to occur but it wasn't due to slide protect because I had it happen twice with an aggressive slide protect and once with no slide protect. The vast majority of snaps were blocked the same regardless of the call.
The Stretch tended to produce similarly consistent results regardless of calling a slide protection out at the line of scrimmage. Due to the safety being in the box and on the strong side of the formation the TE would typically fore go the double team and instead would jump out and block said safety on the edge while the FB would proceed to head towards the second level and attempt a block on an OLB. The only time this changed was when the TE would get pulled into a double team animation but again it was random and occurred at various times even when there was no slide protect.
I don't see it, even when I test it. The location of defenders seems to have more of a role on the blocking schemes than slide protect does when it comes to the running game (and for that matter sometimes even in the passing game).
While I'd love any kind of demonstration if it involved actually playing a human opponent, I'm currently in a situation that makes it impossible for me to play online. If we did play you'd probably just show me what playing a consistent human opponent results in when you play against someone who has had very little exposure to intelligent competition over the last 4 months.