Getting started , GB unlimited and weight training?

Hello! I am new to Gymnastic bodies. My background is weight lifting for years. The last routine I followed was 5x5, but I felt stiff all over, altough I really enjoyed the gains in strenght and muscle mass. Starting with the GB unlimited training has been hard because my flexibility is awful. Have noticed my muscle volume form weigh training is going down. I remember listening to Coach Sommer talking about some minimum days to restore connective tissue...my question is this..how long should I wait until I can make some weight lifting again as a means to maintain muscle mass? has anybody succesfully combined the workouts in GB unlimited with weightlifting, specifically big compounds like deadlifts and squats? how does a week programming combining both would look like?