Buggy walks aren't always as successful as they night be. Its because of the non consistent movement. You get the movement on a walk, but there is change a in speed, direction, pausing to cross roads etc, sometimes uphill, sometimes downhill and so on.
Ideally you want a really consistent and even paced, even tempo movement, ideally to the beat of your resting heart rate. That sort of evenness is almost impossible to achieve on a walk.
If you want to keep cot naps, then you could do with spending a few weeks sitting by the cot during the nap and watching baby like a hawk.
To catch that transition between sleep cycles means catching baby before waking up. The "tell" of leaving a deep sleep is usually a slight movement. It might be rolling over, stretching an arm/leg, It might be screwing their face up or making fists with hands.
You have to catch that tell before it progresses. The transition from deep sleep > light sleep > semi awake > awake is quick. The ideal is to go deep sleep > light sleep > (intervention from you to help) > deep sleep. So catch baby before becoming awake or even semi awake. Semi awake might be a groan or slight noise and it's possible to get back to a deep sleep from here, but is harder. Once baby's eyes open or makes a cry, baby is awake and it's too late to resettle.
You have to be very present and attentive to spot the transition from deep sleep to lift sleep, before waking up. Then do your settling method (without moving baby) to resettle into the next sleep cycle.
What do you do to settle baby? The usual for in cot settling is hand on chest and patting.
One sleep cycle is usually 30-45 minutes so I'd guess your naps are all one cycle only.
Speaking as a mum of 4, I've a fair bit of person experience of settling a baby for nsos while having a busy/noisy house with other children. I personally found it a lot more conducive to family life to have baby napping in the bouncer at my feet, rather than having to keep hiding away in the bedroom to settle/resettle baby.
Also the added bonus of baby quickly learning to sleep through noise, helping avoid them bring a light sleeper. I didn't move to cot naps until settling was quick/easy and no resetting was needed. For me, this happened around 6-7 months, but we had been practicing nap resettles from 3-4 months.
But I appreciate all families work differently.