I also had to ST for naps similar to what you did and in the end it worked! Naps will lengthen and your routine will settle once ST is completely successful and baby is sleeping independently. The difficulty with the 9-11 month stage is the huge physical development that happens around this stage and like you mentioned, teething! Oh the joys!
To summarize what you responded:
you are keeping WU the same at 7-7:15
A times 3hr
patting to sleep for BT and naps
waking a few times a night
Sounds great what you're doing with EAS- eating after sleep not right before
-Set nap times and BT- suggestion on easy below. (he may not fall asleep until 3.30 or 4.00 A from start of nap, but it may pay off if you try it the same time every day, and it will eventually work so that he starts dozing off by himself at the BEGINNING of nap time)
-Set WU time within 15 mins
-For the patting, I got this great advice from a friend here... we would pat, then slow down, and lift hand. Then counted until baby started fussing. If it was 30 seconds, I would pat, then lift, and wait AT LEAST 30 seconds to pat again. It worked for us, as we got up to the 100's and eventually he didn't need any patting and he put himself to sleep.
-During hard core teething- inflamed gums and whites of teeth showing through gums, crazy drooling and gnawing- I medicated for naps as well as night sleep. Tylenol for naps, motrin at night.
How does that sound? Did I miss anything?
I agree with FPT that the sleep cycles will connect given the right routine and knowing how to sleep independently. If you think your son's cycle is around 50 mins, I would go in at the 40 mark and once he twitches, lay your hand on his back firmly. I had to do this and even had to apply pressure to his legs and arms with my body... like I was holding him laying down, until his breathing was slow again. I can't think of a reason not to do this while ST, but I do know that ST can help babies do this on their own. I would only do w2s for 3 days or so, then see how he does on his own. Btw, once my son was able to fall asleep on his own, when he woke at 30-45 min or so, I would wait another 30 min to see if he'll fall back asleep. If he started crying, I would go in and try the patting method, then leave again. Again, after things settle, we'll see how much he is napping total and go from there.
Here's a description of what BW suggests, I just had to modify it bc my baby would almost always wake up. How do I address habitual wakings? (wake-to-sleep and other methods)
Sample routine for your son:
WU 7- 7:15
Nap1- 10:15 (start at 10:15, it may take 30+ mins, but just start here every day for at least a week)
Nap 2- 2:30 (if am nap was 30-60 min), 3:00 (if am nap was 60+ min)
I know this is a hard push, but we'll be here to support you. Come and tell us how your days are going and we can tweek if necessary. But at the minimum, we suggest sticking with a plan for 3 days, but with ST I would say 5-7 days, depending on how it goes.