I was super excited because I recently completed my first cycle for F1 and am now doing the cossack squats and straddle ups. However, my flexibility on both of these sucks. I can keep my legs straight on the straddle ups but am unable to compress all the way. On the cossack squats, I can go all the way down, but I can't keep the non-squating leg straight on the way back up. I feel like that is at least partially a strength issue, but I also know that my flexibility in that area is poor. I've started repeating the first microcycle for each and believe that will help, but what are some good additional stretches to do that will help with these two issues?
And additionally, for the straddle ups and the straddle hold, how wide should the legs be at minimum?