Great
Ok, so the 45 min naps could well be a sign of needing a touch more A time, or waking for the paci, or they could simply be developmental in that he hasn't yet learned to transition smoothly through the sleep cycles. I'm tempted to say either developmental or waking for the paci if he never naps longer than 45 mins - what do you think?
Have you tried being there while he naps and as soon as he starts to stir doing shh pat or applying gentle pressure to his upper arms (holding through the jolts) to see if he can make it to the next sleep cycle without waking? Or you could try wake to sleep, perhaps stirring him very gently at around 30-32 mins?
Routine wise I would suggest that if you want to ideally keep a 6pm BT, you should be looking to start your day at 6/6.30am. Taking 6am as WU time and an average A time of 2h15, assuming longer naps develop, your day might look like:
WU & E 6am
A
S 8.15 to 9.45
E 9.45
A (nursery run 10am)
S 12pm for 1.5-2h
E 2pm
A (nursery run 3.15)
S (catnap) around 4/4.15 for 30 mins
A
BT 6pm including feed
Obviously if naps are shorter it gets a bit trickier, and you will generally need to do a slightly shorter A time after a shorter nap, and offer an extra nap in the day. The day could be more like:
WU & E 6am
A
S 8.15-9
A
E 9.45 (before nursery run)
A
S 10.45-11.30
A
S 1.15 -2pm
E 2pm
A (nursery run 3.15)
S 3.45-4.30
A
BT 6pm including feed
As you can see with short naps you get more of an EASAEAS pattern which is fairly common around this age - as long as you are avoiding feeding to sleep you won't be setting up any bad habits
What do you think?