I have had this situation so many times, someone come to me, right before we start rolling, usually someone bigger and stronger, and says "Can we go light? Just techniques?" and of course I say yes and the person goes crazy fast and with a lot of strengh LOL
So nowaday when someone ask me this, usually what I hear is: "Can YOU go light, while I try to kill you? hahaha
I also don't like when someone make a request like: "Please don't attack my foot, is a bit hurt"

Sure, no problem.
What is the first thing the person does? JUMP on MY FOOT
But in the end, when you experience enough those situations, it end up being almost funny. Almost...

This is a pretty cool parody that ilustrate similar situation