I still need to build a cloned TOC and Index, and set up chapter headings for the Preface and Appendices and Glossary, but those should be minor.
But now I am giving some thought to practicality. And I think that other writers in the group will have a hard time with two things on the format so far. One is switching between print and non print views, because in the non-print view, the headings that are in the sidehead for printing disappear off the left if you click the Web layout. They are still there and re-appear if you click non print medium, but it is disconcerting. The second thing is the complexity of putting in note and caution tables so that they overlap into the sidehead. It can be done, but it has to be manually applied as best I can tell, because a table stylesheet has no way to set a negative margin, and no place to store a sub-class setting
Because in Frame we use AutoText to add these tables from a menu, and it does so with one click, it seems that writers will resent doing the extra machinations to achieve this. Sure I can add the table formats to 'My Templates" which I have urged writers to use (but they don't - they copy tables in from other projects and end up with build errors because they drag along a table stylesheet from another project), or I can make snippets and tell the writers to change the snippet to text to enter content, but they ignore that method. That is with the simple tables we use now in our help; they might freak if they had to apply a table style and then a table class. Not sure I'd blame them, when it is one click in Frame.
And what is 'this' really? It is a holdover from books our company published in the 1970s, quite frankly, and in my opinion, a poor use of white space. Our software books that are still printed (just two per product now) are published in a 7.5x9 custom size, and a wide left side head just wastes space, in my view. 1.75 of a 6 inch width is a lot of real estate, and it translates into extra pages printed per book. Even worse, all of our PDFs for software have a matching format, so those PDFs are likewise inflated. And all this just to accommodate Heading1 and Heading2, both of which are larger in Font size, different font family, and different color. Sure they stand out, but so does white socks with an Armani suit (not that I would know one or fit into one). That and the Note and Caution tables, each of which has a large graphic and a background shade to distinguish it. And oversize tables, of which we have many, already stretch into the sidehead, and are more finicky because of it.
All of that is a long-winded rationalization for my plan to propose to the group ditching the sideheads. For the books that will remain in Frame (the hardware books, at least half of our output, are already single sourced, in that they do not ship as help), changing the Frame template will just slide most things to the left a bit, and only the page breaks will change. For the software books and help, I think the look will be better, the books fewer pages by some (as I might increase the vertical spacing for the other headings to open up some white), and the formatting in either Frame and Flare will be easier.
Right now there are two books/help outputs that will gain much by full single sourcing and conditionalizing (4 outputs from 1 source for each). The others will be helped by generating less formatting work for the other authors, who will be able to seamlessly write in Frame (by choice) and import to Flare, because we will be using one combined set of style definitions, rather than two very different ones (one Frame and one inherited from pre-Flare RH). What will happen is that their content transferred to help will automatically show up in Verdana in the non-print view, while it was (and still is) Book Antiqua in the print medium.
At the same time we will be ditching chapter-page numbering for continuous page numbering to match our PDFs, losing another archaic remnant of days gone by. I had no problem implementing 1-5 in Flare, but I have been an advocate of the book matching the PDF for years, and had to bite my tongue and bide my time. Now they are powerless to stop me! (Sorry about the meglomania.)
Seriously, I have not had much trouble convincing the other writers, and showing them some usability articles from this century really helped.