flushing is irrelevant to harvest... you flush if there's a problem. if you want to use up nutes in the substrate, just use plain water but don't get excessive runoff - can avoid mixing nutes and still give building blocks for growth.
starving a plant, even if only for a short period of time, is guaranteed to be a net negative in the context of any healthy plant... some toxic mess is irrelevant as that is a mistake made long ago and continuously ignoring it over time.
can't see the buds at all, so it's as if you didn't include a picture. looks a bit hairy in the far away blur, so you probably have more than 5 days remaining. the question will be are you stripping necessary bulding blocks for the plant away too soon? spontaneous manifestation was proven false by pasteur long ago. law of conservation of mass applies here. no molecuels to build cells, or fewer or harder to source, slower the growth will be. ripening is growth. can't make something from nothing.