Bike set up post shoulder surgery?

Hi there, I’m staring down the barrel of shoulder surgery with a long, long recovery ahead of me. I’ll be cleared to use an “exercise bike” after a few weeks but I’ll be in a sling and will not be able to put any weight on my hands, or even reach out to the bars. Has anyone been through a shoulder surgery and maintained fitness after on the trainer. If so, did you make any modifications (changed saddle/stem/bars) to your bike? I’ve ridden sitting upright in a sling several times and it’s doable for shorter time periods, but trying to do longer rides is more than a little uncomfortable on the sit bones and bits. Thanks!

I know this is not the same thing but I wonder if a similar solution might work for you. This article talks about how one Zwifter mounted tri-bars upright on their bike so that they could keep Zwifting while pregnant. (check out the picture to see what I mean). This resulted in a much more upright Zwifting position for her and I wonder if something similar might allow you to protect your wounded shoulder while giving you something to hold on to to help with bracing yourself with your good arm in a more upright position.