The goodman handle is one reason it won't meet spec ... but a more important (to my concern anyway) reason would be the overvolted design and limited burn time (70 minutes) for the 50W light. Also, you would need to make some (admittedly minor) modifications to accommodate mounting the light on a waist strap ... at least, the ones in the pictures show mounting hardware that's designed for a backplate or tank mount. While this wouldn't disqualify the light, per se, it does add one more necessary modification that other lights would not require.
I'm not saying these aren't quality lights ... I am saying that GUE is very specific about the type of equipment they want DIR divers to use, and that this light isn't designed with those specifications in mind.
I can think of more than two manufacturers who make DIR-compatible lights ...
... Bob (Grateful Diver)