Try this for a while. Let's do push/pull/ legs, push/pull/legs, day off. Cut the number of sets. 2 sets per exercise same exercises, keep reps at 20+. Tell me how squats go. We will improve the depth as we go along. Try step ups, and negative (down the stairs) with the repaired leg.
Between 35 and 45 minutes (sometimes people come and talk to me -- I hate it but have to stop).
Bags, I'm not afraid of the knee but I already have tendinosis and I don't want to make things worse. I do a bit of legs every day (weightless leg curls and extensions) and I isolate them twice a week like m_b told me to.