@The ADD I did the extensions after squats and leg press lol. I have to do moreThis.
If you're willing to do something a bit different in the gym, I find the below workout helpful for recover:
https://www.t-nation.com/workouts/neural-charge-training
but you have to treat it lightly, its not intended as a hard workout.

Yeah, I usually alternate upper and lower along with push/pull when applicable. Thanks.