Hi there.
Here's some info on the 4S wind down.
What does a good wind down consist of (Includes 4S ritual)Prior to getting my dd to bed, I do the same set of activities so she knows its either time for nap or bt. For example for naps, I will do a diaper change, read stories, put her into her sleep sack, then lullaby and then crib. I lower the blinds before nap time because I find it easier.
When I was sleep training her, I would have to shh pat her until she was drowsy and then put her down. I tend to not use pu/pd. if she starts to cry, I would continue to shh her and rub her tummy since she's on her back. I'll do this until she's calm and then see if she falls asleep. If she cries again, I'll go back to shh rub. If she got frantic, I'll pick up and do the shh pat until she calms down, put her back into the crib and then do the shh rub.
Our bt routine is bath, bf, story, sleep sack and bed. Again for calming I would do shh rub when she's in the crib.
Wrt shh pat becoming a prop, I suppose if you always use it to put her to sleep before putting her down, then yes. But if you use it to calm her and make her drowsy and let her fall asleep on her own, then no.
Hope this helps.