He is too young for 1 shorter nap and 1 longer nap really - although some low sleep needs LOs do end up doing something like this.
I would try for both A times before the naps to be the 3hrs as a standard routine for 6 months. Maybe try the W2S on the second nap if the first nap is now steady at 1.5hr+ each day. If you can extend nap 2 nights should be a little easier.
The night feeds could be linked to a GS or to the solids being introduced.
Are you giving water or milk after the solids? Some LOs like to finish off their solids meal with milk so perhaps try that.
Another thing which could impact on nights and hunger is having dinner - you could drop the dinner solids (reintroduce later) so that he is properly hungry for his milk and fills on milk instead, which could help see him through the night like he was previously. Like I said a night feed is normal so this isn't about actively dropping a NF but rather just making sure that the day calories are the best they can be.
What a time should we do if only get 45 min afternoon nap before doing cat nap?
When you move to 2 naps it is really hard to fit in a third nap/CN if one of the other naps is short, just because you start getting near BT.
It may be easier to try to extend nap 2 and if unsuccessful go for EBT. You likely need to start the BT routine almost right away after giving up on extending. Something like:
S 2.45 - 3.30 (45 min try to extend)
try to extend for 30 - 40 min
4.00/4.15 stop extending, move on.
A this A time counts from nap wake up, 3.30pm and needs to be no longer than 3hr max, ideally shorter, say 2hr 30 (due to short nap)
feed, bath, pjs, wind down and BT feed
BT aim for sleep at 6pm (and no later than 6.30pm)
hope this helps