All of the boulders in my gym are actually around 2 grades below their given grade, I don't understand why they give them the higher grades and not the actual lower grades. Is there a reason for it?
What really helped me get better at sit starts was climbing on a moon board, and either finding boulders that have sit starts, or building new boulders with sit starts.
I was pretty bad at sit starts since they are very compressed for me, something I am fairly weak at. But after climbing for about a month almost only on the moon board, I really saw the improvement, and it was very noticeable.
I still work quite often on the moon board, and I can really see the difference from before and after. I try to do the most disgusting sit starts possible on the moon board, and I can do all of the sit starts on the regular route setting walls.
The moon board in my gym is a 30 degree angle I believe. If you don't have a moon board, I think you can probably do the same on any other system board.
I sort of unlocked the v6's after 6 months actually. It was a pretty solid v6, and after that, it was as if this whole new world opened up and I was able to climb even more v6's. Of course not all, but some, and others I was able to do a few moves, while before I was struggling a lot on v5's.