You put one non-tk name in the font page 'Configuration attributes'.  I removed it as not belonging with the tk Vars, but it got me thinking that more would be useful.  In the ConfigChanges docstring we included a list of methods, which I believe is recommended even if not always done.  If we turn the check_ functions into classes, their docstrings become the class docstrings.  The check_ body would be turned into and __init__ body and the list of methods would the methods that need to be moved into the new class.