Peter, I agree it would add an extra layer of time. The benefit of it would be weighed against the additional time added.
The benefit of it is that it would put number hitters, and pushy clients, at a severe disadvantage. The ethical and competent would have a more level playing field to compete. Over time, the agenda drive appraisers would be much easier to track and expose with this system. Right now, they slip along, year after year, under the radar, unless an old ugly report catches up with them.
If the phased assignment added time, it would be even across the board. Right now, the only one spending any extra time is the honest appraiser who dares not make a SC price. Meanwhile, Mr and Mrs number hitter are churning them out at a rapid clip.
I think it would benefit the good guys and the small trade off of time would be worth it. The number hitters would be the ones that would be seriously bogged down in a time suck, as they frantically try to pull 100k out of the air to add to their previous MV when they see the inflated SC price! Dang, they could have fudged in that 100k right from the get go if only they had the contract to start with!
IF the extra layer of time is accepted across the board in purchase appraisals, it would be customary to include it in fee upfront. (I find many appraisals come back for a second pass these days anyway, for one reason or another)