Much easier to get them to hold the collective differently and tick a box but you are setting them up to fail.
If you can address the issue of a student being tense on the collective by getting them to adjust their grip, why wouldn't you? Many students are nervous in the early stages and all you have to do as they gain experience and confidence is introduce a better hand position or make sure they understand that when they need to manipulate the throttle, they does as Robbiee says and slide their hand up the lever a bit.
So much better than constantly having to nag them about death grip on the throttle.
I teach people to hover over the water (not in a Robinson I might add) with a low grip on the cyclic to reduce overcontrolling but they understand they have to adjust their grip slightly if they need to use any of the buttons at the top of the cyclic.