The 'use it' instruction was introduced to stop a team winding down the clock by holding the ball stationery at the back of a ruck with nothing happening.
My view is that a team bringing more players into the ruck for a tactical purpose (caterpillar or not) is, in fact, 'using it'.
I think it's a blight on the game, and is one of the reasons I prefer NRL to most of the Union currently available on TV. If a scrum half can't get a box kick away from the back of the ruck without it being three body lengths long, then two things needs to happen:
Referees need to enforce the back foot law, and scrum halves need to improve their technique.
Union is some kind of spiral with laws and applications: all these changes of emphasis, or the messing about with scrum stuff, is happening simply because Elite referees have failed to enforce basic laws.
Fail to enforce back foot law - fringers encroach - 9 decides he needs more protection - long caterpillars - being forced to use it when told. Stuff that wasn't necessary years ago.
Sort out the first bit and the rest of the chain colapses.
