> Anyone have any big picture thoughts at this point?

Yes.  For years, I have wanted major changes in out tkinter docs, but making them myself has never become a top priority for me over working directly on IDLE.  The latter has been hampered by the inadequate tkinter docs.  Fortunately, I have learned to interpret the online tk docs.  But I would be happy work with you, Mark, to make something better.  My perspective is that of an competent but occasionally user who cannot keep all of tkinter in my head and needs a good reference that does not currently exist.

(I am currently working on two other writing projects, but one should be done in a few days.  So I should look at your proposals within a week.  I already reviewed and critiqued Mason's PR.)

I would like a complete, in some some sense, internal reference, which would would be able to correct ad further improve.  Complete means everything in the Shipman 8.5 references, but somewhat rearranged and more compact. Current references both external and internal, are variously obsolete, incomplete, and buggy.  The latter two apply to our internal ttk doc.  All external references suffer from being out of pydev control.

I don't see the tcl/tk versions as an issue.  First, the 3.x *tkinter* docs should document the features available in the 3.x version of the tkinter module.  It could mention that it should best be used with the most recent tcl/tk 8.6 possible.

Second, the Centos is about the only *nix distribution not having 8.6 available.  On another thread where the question of using something new in 8.6 came up, someone posted a link to a site with distribution versus tcl/tk information.  Unfortunately, I cannot find it.  The 8.6.z releases mostly add bugfixes.  The new-in-8.6 features listed on https://www.tcl.tk/software/tcltk/8.6.html should be in all or most all of 8.6.z releases.

My 'biggest' idea is that we should document tk and ttk widgets together.  I don't think we should continue to treat ttk as just an optional, and by implication, 'advanced' add-on.  Each entry should be labelled tk, tk&ttk, or ttk.  Or perhaps there should be 3 subsections so labelled.  The ttk doc only has widget entries for ttk (only).  Perhaps the authors felt that full entries for 'tk&ttk' widgets would be mostly redundant with docs for the tk versions.  I agree, and propose entries that cover both.

We should expand on what the ttk doc does in separately documenting options common to more than one widget. I would like to add 1) a table (matrix) of common option versus widget, with marks indicating which option can be used with which widget, and 2) links from each widget doc to the blocks of common widgets it uses.

The initial chapters of Shipman are mostly about possible values for some of the options.  These belong together in the 'Options' subsection.