ok thats really helpful...should I be increasing every a time by 10-15min or just the morning one? So far I have just been increasing the first two a times then seem to spend the rest of the day putting him down earlier and earlier as trying to catch up before evening
I personally always did all the A, but if that works better for your LO then do that.
still seem to end up with a very overtired baby in the evenings. And even if he seems really overtired should I keep going with the new a time every nap for 3 days? In the end should he then start taking proper length naps then after these three days?
You mentioned that you are trying to let him catch up on sleep, right? How are you doing that? Is there any AP or props that will work?
The best would be to let him catch up on sleep and then start and increase the A.
In theory yes, you are sticking to the longer A even if you had a couple of OT days. After 3-4 days you need to see if you are getting again UT naps - then you do another increase, if naps are good - 1.5-2h then you don't do anything, if they are still OT (30-35min) then you either stick to the A for a few more days or go back to a shorter A.
Do you think Im right to put him down early to try and get rid of overtiredness first and then try again with increasing activity time once I have this sorted?
Like I said, I think you are right to do that, but you need to be cautious there because many mommies are confusing UT with OT. My DS yawned throughout his A and I was always sure he is OT but he was US and bored, he needed more A and to DO a bit more in his A then just lying around.
he seems to forget how to fall asleep when I keep him up this bit longer
IMO it's always ok to AP and use props if you aware of what you are doing and willing to deal with the consequences. If he used to fall asleep interdependently and is now not it could be that you put him down UT or OT for his nap and then he needs help falling asleep.