Thats the only way to get it done - these guys pay no respect to what you say or do. The best way is to get teach them that you can do it too. Then they work proficiently (I dont know why).
I remember long time ago giving a car for a mount fabbing job as I had badly injured my right hand, and the guy was giving me lectures on how the V6 I was putting into the galant was a pain and the mounts need to be this and that.
I said leave it, got a freind to help me and I made the mount frame on cardboard and glue with one hand in bandages - got someone to cut the metal sheets to size - mock up welded them - test fit - little fiddling done - reweld completely - press/bolt in new mounts and put the car on wheels - The same lecture guy stood there and did not bother to even help. I removed the car from his shop the same day.