According to wozzvt's study...
Guard skills: HA helps OD, PA, DR. DR helps JS. OD helps HA.
Big skills: IS helps ID, RB. ID helps IS, RB. (It appears that IS's effect is larger than ID's)
He didn't suggest that there was any difference for height, so 6'8" won't matter. 1v1F is fast-popping training which trains 4 skills that benefit 4 guard skills and 2 big skills. So I highly recommend it until HA/DR are high enough to give you a little boost at the beginning of any SF training, along with the regular hole-filling, and then launching into big skills if your short or guard skills if your tall.