I self rehabilitated ski girl.
I did keep my surgeon up to date with my info/updates bi-weekly or so. I was not lifting much weight, but doing more body movements. After all only my sternum (bone) and heart and aorta (tissue and muscle) were operated on. Yes, vital parts of my body, but just like eveyrything else, and I mean every other injury a person can have, be it surgically or self inflicted (accident), EVERYTHING heals and heals at about same rate for each individual (individual dependent).
As my body let me know that I am ready for more, that is only minor ache from my activities, I pushed on. Doctors can only advise based on guidelines and personal experience, and they would give slightly different advice to themselves as they know themselves better than you or me. I made sure to introduce myself to my surgeon and make sure they know as much about me as possible, I sent them my training videos, my competition results, my self-collected bio-data, etc. I made sure to discuss those things before surgery and explain my goals and see what they say. I was looking for a reasonable surgeon that would be honest with me about my expectation and understand where I am and where I hope to be. One thing I liked about my surgeon is his honestly. There was one conversation where he said: "You know, that initial time post OHS will SUCK, and SUCK bad. You will loose lots of lean muscle as your body will be in a fight or flight mode, but you will recover." He also said that it will be safer to train post OHS with my parts repaired and that there is "NO REASON" why I would not be able to get back to 100% normal. I am off topic, but I think it is important to be honest with yourself, take all the inputs of the system, process them, and come out with safe outputs for each individual. Main thing is to press on and recover and get back to or in to a great condition.
Here is what it all boiled down to for me. If you tear a muscle, and I mean an average tear, you get 2-6 weeks off, if you break a bone you get 4-12 weeks off, etc., etc. So, post OHS you follow the same speed of tissue healing as anything else. The damage we had is a serious one, but the more you are active in any time during recovery the better you will get and be.