Richard, don't know how it might fit in (if at all) but I know some folks use a push stick when doing rough in grinding. I tried this a couple of times and either I wasn't smarter than than the stick or I just wasn't doing it properly but I ended up learning a lesson the hard way. The stick slipped off the metal and when the belt hit it the stick turned downward and the heel of my hand then went into the belt.
You may address the proper way to use such a stick, or how to build a reliable one, or possibly you may not recommend the use of them at all.. Like I said, don't know if you can create a safety tip from my misfortune but if so and it helps someone else avoid this kind of mistake it would be appreciated.