Hello and welcome to BW forums
It does look like a good time to move to 2 naps.
I recently bought a book called save our sleep & have been trying to follow the 6.5 - 9 month routine which has sleeps at 9:20am & 1:20pm. The book indicates to not put baby down untill these times reargless of whst time he/she wakes so I have been doing that.
Sorry, I can't comment on this book as I don't know it. What I can say is that the EASY routine is not a strict schedule of times in this way but rather it is adapted to LOs individual needs. I would seem that this strict schedule has helped you to get a longer first A time and a better first nap though.
Based on the information you've given I'd say your LO needs at least 3hr 30 first A time. He got 3hr 30 A time with the 5.50am WU and 9.20 nap and was trying to extend his nap to 1.5hrs but that seems to also be after a period of wakefulness in the night. I'd probably increase the first A time a bit to see if it helps him get into that next sleep cycle but rather than have a set nap time (of 9.20am) I would adapt the nap time depending on his morning WU time until you get a more consistent 7am WU.
The second nap is coming too soon IMO, his restlessness for the first half hour or so looks like he is under tired for that nap, which is not surprising as it does come pretty soon after his first nap. The restlessness until 2pm looks like he's extending his own A time, so roughly 3hrs from 11ish until 2ish. Again I'd prob give him a good 3hrs before put down to help him have a proper nap.
Based on that info then how about something like this:
WU 7.00
A 3hr 40
S 10.40 - 12.10 (1.5hr)
A 3hr
S 3.10 - 4.40 (1.5hr)
A 2hr 20
BT 7.00
I know you've said you want consistency to the day but it's difficult to suggest a 'fixed' time for naps when we are not really sure how your LO will react to the times. This sample routine is a bit of guess work from the info you've given, a starting point, after you try it out we'd look again at how it's going and see if he needed a bit less/more A time somewhere in the day or for example a slightly later BT to help with those NWs.
The routine above is written out as a 7am morning WU. If your LO woke earlier you would need to amend the times accordingly so that the A times didn't get too long. EG with a 6.30WU you need first nap at 10.10am to maintain the 3hr 40 A time. As the last A of the day is shorter you would have a little leeway there to maintain close to a 7pm BT but again it is not a set time, I would not let the last A go over 3hrs at this point (the same way you have recently altered BT based on nap times).
It does take some flexibility but hopefully would settle down into a more predictable routine with basically the same times each day.
What do you think?
also here's a link to guidance A times
Average A times- BOOKMARK ME! You'll see at 7 months some LOs are getting more than 3hr 15 A time, just depends on their individual needs.