It's very early to be doing exercises anyway,
@mopa . I'm glad you're taking control of the amount of exercise you will do.
My surgeon doesn't allow any PT at all for the first month after a knee replacement. He says your knee needs that time, to start on its journey of healing. For that month, we rest, ice and elevate our leg, and walk around the house. We don't just lie around like logs, doing absolutely nothing.
After that month, we just go to PT once every 2 weeks, where we are shown a few new exercises to do at home.
His patients all do well and achieve good ROM, as I did, and he hasn't had to do a manipulation to help with ROM for the past 4 years. I think that speaks for itself.
After my left TKR, I didn't do any formal exercises at all. I just used my knee doing my normal activities of daily living. The result was just as good as when I went to a few PT sessions for my right TKR.
I think that one reason why the PT therapists are so hung up on exercising and measuring ROM is because increasing ROM is something they can use, to demonstrate to the insurance companies (who pay them) that their ministrations have been effective.
They've been taught that the exercises are essential, and they believe that.
There's nothing wrong with doing exercises, provided that the amount and type are adjusted to each person's level of recovery, and the person doesn't experience any pain or increase in swelling, at the time or later.
Unfortunately, many PTs use a sort of cookie-cutter, one-size-fits-all, progression of therapy.
Too much exercise, too soon, causes more harm than good.