I have started the 5's pro + supersetted FSL base cycle like you adviced. Supersetting sucks, but I have done my workout under 60 minutes (mobility + speed work included).
In the thread you mentioned 5's Pro with 25-40 reps of FSL. My question is: Can I add the volume in pressing-movements (starting from 5x6 and going from there)?
The 5x5 is definitely enough for DL/squat, but since the weights are so low I feel I could do much more for the upper body.
I have just done my first week, so I'm not jumping to anything yet. Just thinking that for future (or in next cycle) I could do this. The idea is build some muscle and work capacity after all?