Is it actually possible once you’ve spent time on a board to flash problems? You’ve grabbed all of the holds, done many of the moves, maybe even the sequences. At that point can you still “flash” a boulder? What if it only has one new move you haven’t done? Is that still a flash? 
Outside, many say no if you’ve done the sequences - you can’t then flash a variation. Should it be different indoors vs. out?? 
I say: if you’ve done any of the moves on a boulder (same starting handholds, same starting footholds to the same handhold) then it’s no longer a flash.
Other than that, flash away.
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Agreed. If not, I’d just make up several boulders that have all of the overlapping parts and dial those so that I could flash all the benchmarks. 
File that under the “tactics” board
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