I quite like this idea too.
I'm sure there will be some people who will moan about 90 being too far away, but as laylay pointed out, it would be pretty pointless for 7x and 8x since the equipment is so easily seceded.
Also, while I hate to say it, it may be necessary for officers or some other designated person to do the refining, so that some don't simply treat it as a cash bonus. In that sense, the reward we're offering is a free upgrade to +5, not orbs.