I think that the Burgess books are important, for they begin to teach dc to listen to books that require more attentive concentration.

I believe your ds is showing a need for that skill to be developed, as my dc did too at the start of the Burgess books. I remember one of my dc not realizing there were 2 foxes in "Reddy Fox" even when we were almost to the end of the book. I believe he asked why Reddy Fox was wearing a skirt or something. I remember saying none too patiently, "Because that's not Reddy Fox, that's Granny Fox!"

And he said, "There are TWO foxes in this book?"

However, this just made me realize we had to work on this skill more, a lot more.
Charlotte Mason style books often do take more focused listening if they are read alouds, but also more focused reading when they become independent reading. I have come to believe it is because many of us didn't grow up hearing CM style living books, and many of the books our dc have been exposed to are not very CM-like either. I used to teach ps, and it's been funny how over the years of homeschooling those ps books get read less and less and less. My dc have learned to identify living books better than I have, it would seem. Little by little, I've gotten rid of most of those ps books, and gradually replaced them with CM style living books.
I just want to encourage you that many of CM-style skills take quite awhile for dc to become proficient at - like oral narration, dictation, and written narration, to name a few.

The reason they take awhile is because they are worthy of being learned, and they take some focus and concentration to do. So, a few things that helped me with my ds growing into listening carefully while I was reading more CM-style, timeless, kind of books...
- Give a brief review what happened last time (i.e. Last time Buster Bear got his head stuck in the bucket. Oh, my what a mess he got himself into over those fish!) Showing an accompanying picture if there happened to be one is a good idea too.
- Then spark their interest by giving them a cliffhanger (i.e. Do you think he will ever get his head out of that bucket? I wonder what everyone else will do when they see him stuck in that bucket? Let's read and see what happens next!)
- Remind him to listen carefully because you will be asking some questions.
- If he doesn't have a clue what you read, tell him the goal is for him to listen carefully so he can enjoy the story, and then answer questions about it to show he understood it. His answers show you whether he understands the story, so you'll read it again today, but really you are just supposed to have to read it the one time for him. Today will be a practice to learn how to listen carefully.
- If he is still struggling after this, I'd read the one page. Turn over the book and give a quick summary of what's happened, again giving him something to listen for... (i.e. Well, everyone is laughing at that Buster Bear now! I feel so sorry for him - can you imagine how embarrassed he must be? I bet he's wishing he'd been nicer to the other animals. Let's keep reading to see if he ever gets this bucket off or not!)
I hope something helps here, but here is a past post that should give encouragement too:
viewtopic.php?f=6&t=126&p=512
In Christ,
Julie