He's back

Mate, if I could train 6x per week I'd be inclined to do 1 muscle per workout. You're an experience lifter so it doesn't have to be different just because you've on and off for a while.

I train 4x and add bi's to chest and tri's to shoulders.

If I were in your shoes I'd prob go 1 group per workout and whatever time I was saving would be jumping on some cardio afterwards to start dropping that bf down! Maybe even a 5 day split and and using the 6th day as cardio only.