Also, PT pointed out that a person with s partial as opposed to total knee has much more ROM etc just by virtue of what was done to the knee. Therefore, they are sometimes able to do some exercises sooner.
I'm sorry, but your PT is wrong about this. There is no difference at all in the amount of ROM possible between a PKR and a TKR.
Even though only one knee compartment is replaced in a PKR, the surgery is almost as traumatic as for a TKR. Your knee is still opened up, soft tissues pulled aside, your kneecap turned over, and the ends of two large bones sawn and shaped.
With a few exceptions, recovery from a PKR is just a long and difficult as recovery from a TKR.
I have had a PKR, a Revision to TKR, and a TKR on my other knee. Of my three recoveries, my recovery from the PKR was the most difficult.