Hi there- My daughter is about same age as your lo and I've only recently transitioned her to the 4hr routine. It's only been a couple wks now and she's adjusted very well although like you, naps are an issue. Back to naps in a bit...
What I did was i slowly increased the timing of next feeds by 15 mins, starting from the 2nd morning feed, eg. instead of 10.30am, I moved the feed to 15 mins later. And I stuck to that for a few days before finally getting to 11am. When I moved the mid-morning feed, I'd keep the rest of the day at 3-3.5hrs so that she could adjust. However, if she wasn't taking a full feed at say 2.15pm, the next day I'd move that one by 15 mins increments until I reach my goal of 3pm. From there, I finally reached the 4hrs per feed and she now drains 6oz each feed (which seems to be around normal intake for baby this age).
The only variation to our 4hr routine is that the final feed of the day isn't at 7pm for us, at least most of the time. Because I bathe her a little earlier and give her some quiet time, I end up doing final feed by 6.15pm and then just put her straight down to bed. According to BW, it's ok in this case to feed to sleep as long as you don't do this for all your other feeds and make it a habit. This has worked very well for my lo although sometimes, she's much too tired, in which case, I put her down for an extra catnap even at 6 or even 6.15pm for only 1/2 hr and then get her up for the final feed. Either way, her night sleep has not been affected. Dreamfeed is about 11.30pm for her and she sleeps thru til about half 5am but wakes not out of hunger. W/ paci, she'll settle again and sleep til 6.30-7am.
As far as her activity time, it's been a real learning curve because she does get tired before the nap times as outlined in BW. Initially, I'd just keep her up for 1hr and 15mins and from there increase the awake time by another 15mins w/ quiet time, e.g. music, cuddles, soft toys etc. It's tough because to entertain a fussy sleepy child is no ride in the park! And of course, her naps do get affected. Depending on her moods, I will keep her up the extra 1.75hrs. But only now, I'm starting to trust that she will adjust herself because there are days when the 4hr routine works to the T.
Her naps are an issue for me now as she just can't get past the 45mins cycle and she ends up getting at least 2 catnaps before the next feed. In any case, I'm told that the 45mins naps are a common occurence for babies this age and eventually by about 5-6mths, everything should all come together. Only thing is, I want things to work perfectly yesterday!!
I hope this has helped a little to give some insights. Believe me, at your lo's current age, you'll be surprised how easy it is to make the transition. Let us know how things go!!
