I think it's definitely worth getting as tight a group as possible, just because as you say when you make choices to play the percentage with the wind. Giving inside edge is fine if you're confident on the range and the ability of pellet to stay on the level you put it, but in the event it does go straight there's not much margin for error before it hits high or low and lands on the upper or lower edge.
Group analysis is tricky because of the wobbly mass normally involved and benching springers is tricky. But using a chrono down range could indicate if a vertical spread is down to the shooter or the pellet. All things being equal, even without wind, a good group should have less vertical spread than horizontal... so it's wider than taller. That's because support in position should be more solid than from side to side.
Given the difficulty or the pseudo science with harmonics etc i'd say the only way to test a pellet itself is to vice up the barrel... which is obviously very tricky. But it does look like there's at least some indication that downrange chrono'ing could be an indicator as to pellet/barrel problems that aren't due to the shooter, or vice versa.
BFTA/NSRA County Coach
CSFTA Chairman/BFTA Rep