@Drabslab
Apologies if it's poor form here to bring back old threads, but it seemed to be the exact right search result.
New user here, and I recently imported a route started in google maps, brought it in via KML file. Some part of the process went wrong and the 50 stops were partly in the wrong order. So I thought I would shuffle in MRA rather than play with KML.
I needed to move about 20, and I was hoping this would have taken me about 90 seconds. with moving some points multiple times, it took about 5 minutes, with the millisecond lag between each move getting more and more painful to experience.
Microsoft excel has an option to switch off auto-recalculation and I went looking for a similar feature, but couldn't find one. It would be a great addition.
I do get that some people might feel that it's just a matter of throwing more processing power at the problem, but there will always be a delay, and we have different expectations of what makes a good experience. Personally I shuffle data like I'm shuffling dominoes and the merest delay feels like trying to shuffle dominoes in treacle. 
When a first quick shuffle is needed, or when brainstorming a road-trip, I would applaud the ability to pause recalculation. Great suggestion.