I'm glad to hear your LO naturally grew out of the short naps eventually. Did you do nap extensions or anything to help that happen, or did it happen on its own?
I did do nap extensions and because I was home all day with him and no other kids at the time, I could...and I was stuck in his room for 30 minutes trying to get him through. It was the choice I made, and it worked. But it was a lot of work and not something I could do if I had other kids or commitments. However, it really did happen one day that he extended his nap all by himself--or, rather, he stopped waking developmentally in between sleep cycles. And I never had to extend a nap again. Can't say that's how all babies do it, but that was my experience, and because I'd worked on gradually lessening the shh/pat at the beginning of his nap, there were no props to worry about once he was able to handle napping longer on his own. So, don't be afraid of the shh/pat.
The leg jerks are as he's still falling asleep or within the first 10 min. Its a toss up if he wakes from the ones within the first 10 minutes, but the ones while he's falling asleep always disturb him.
I think that's still common at this age. What does he do if you leave him to settle by himself if a jolt wakes him up?
Also, while it is true for some babies that they will want to go to sleep again sooner after a short nap, not all are like that (my daughter hardly ever showed sleepy cues and was very content just to stay awake until her next naptime). Maybe your son is like that, too? And not all A times have to be the same. EASY is really learning how your LO ticks. That might mean that he's able to handle more A time in the morning, but less as the day goes on. Or vice versa. If he's waking up in a good mood, though, that doesn't make me think he's overtired for his naps, which is why I think maybe having him stay up for ~1h35 might be the way to go. However, if you try this and it leads to worse naps, maybe he would like a shorter A time in the morning, then more as the day goes on.
So you would suggest first moving his feeds to a 3 hour schedule even if that doesn't follow EAS and then going from there?
Yes, I think he should be able to last longer in between feeds, given his age, than 2 hours. A general rule of thumb is 4h in between feeds sometime around 4mo, but again, all babies are different so there's some flexibility. Is he formula-fed or breastfed? BF babies will sometimes need to eat more frequently, but I still think you could stretch out his feeds. Something like this for his day:
Awake at 7
E: 7:30
A: 1h35
S: asleep at ~8:35
A: awake at 9a-ish (if still short napping)
E: 10:15ish--just before his next nap, though not feeding to sleep
S: asleep at ~10:30
So...something like that, I think.
This age is kinda tricky because there are a lot of developmental things going on right about now. Chronic short napping, growth spurt, being able to stay awake longer, being able to eat more and therefore go longer in between feeds. Plus, you're starting EASY and the shh/pat...lots of possibilities. Hope that makes sense!