When the new schedule format was introduced, I was placed on the Deck Squat (SLS/PE5 of F1), and after a couple months was able to pass the last step. I recently started SLS PE1 for F2, but have found my mobility seriously lacking to the point where I can only go 60% of the target range of motion (without using my hands to support some of my weight). I've been looking through the mobility exercises for F1 (the ones that were introduced after the update) and have found even some of those are difficult for me.
So my question is how I should work to bring my mobility up to speed. I don't need to start at square one for the strength (deck squats are not challenging), but I know my lack of mobility will be the point of failure moving forward. Should I focus on stretching for the next few months, or just keep working on PE1 (Cossack squat) until I slowly gain the ability?
Thanks in advance.