So, the pat/shh method is best when you can access the baby's back. From the descriptions I've read, it sounds like you are placing them on an angle using a wedge of some type, and if you removed the wedge, baby would be on his/her tummy.
When I first tried pat/shh, I had DD on her side, but did not use a wedge. I put her on her back, then lifted one side of her so she was tilted. But if I let go, she'd be on her back.
I've found that pat/shh does work best with the wedge/tummy method. But then I have to put DD back on her back to sleep once she is out, and that often disturbs her and I have to start all over again.
Is it okay for her to sleep in the position that she is in for shh/pat?