Paging - incorporate with CKeditor?

Currently running a large D7 site  and currently looking at how i can move to either latest Drupal CMS or Backdrop. 

I've set up a backdrop cms install on my server and set up was really easy (awesome work on that and the clear documentation ! )

I'm now in the process of testing a number of features/ capabilities. 

Even though its a large site, I  don't plan to "upgrade" (its an option) - but I've used feeds quite extensively in the past and was expecting that i'll likely need to make some changes anyway (especially as some of the design/structure decisions made 10 years ago have plenty of room for improvement)

Backdrop seems the preferred route based on the investigation so far, but i do have 1 items that I need to figure out and that is paging.

currently in my D7 site, we used the smart_paging module (https://www.drupal.org/project/smart_paging) and this integrated into the CKeditor.

with backdrop the https://backdropcms.org/project/paging appears to be almost identical except for the CKeditor integration

for the main article content if use the raw HTML text formatter, the paging module works perfectly fine, and I get a nice paged output.

However if I switch to use the default "basic" (which is using Ckeditor 5) the editor removes the paging tags from the source ( looks to be some "clean up activity when switching between the 2 formatters).

Now ckeditor appears to come with a plugin ( maybe even in its core, I'm not 100% ) to support page breaks ( https://ckeditor.com/docs/ckeditor5/latest/features/page-break.html ), and i'm wondering if i can incorporate the pager button into the CKeditor, so that paging can work?
 

any ideas would be useful to help me figure this out? thanks