Especially now that there are very few 5m attacking scrums (previously almost all for held up, now replaced by GLDO) .I reckon that adult rugby should take a leaf out of the junior guidelines and have a pushing limit. Say 2m
That would give the dominant scrum ample opportunity to get a benefit from their dominance, and dissuade the retreating scrum from dropping or wheeling.
I must admit, I haven’t thought about this very deeply, but it seems a good idea on the face of it
So no real reason to push more than 2m