Breaching without letting the engineers proof the breach? Ah, no. I have been forced to try this for real. Was in a Hummer, part of the first element through, incredibly rough and very slow passage, slow being the opposite of what’s required for passing through breaches, came across a boulder that probably weighed more than an M1 and would have stopped it as it stopped us about two thirds through. It happened in 92 so I don’t remember what the remedy was but I think a valuable lesson was learned by all involved! Proof the breach.
Not quite sure this may be the result in game but other surprises may await!
somebody could try it and post results, might be fun.