Okay ...
so in this case it was the same problem like with breast region of the female characters --- without the helpers you get really weird things except you are doing lingerie or stockings.
So forget about the rigid groups, because when it works fine, then everything is okay.
Btw.: I was not aware that the legs for these boots were "shortened" to create the heel, because I simply never tried them. For my shoes you see that I had done another method (see other thread you've started).
As far as I know: if a character wears heels, he is taller normally
(but for these boots with the small heels it does really not matter, but do not try to shorten the lower leg, when you are creating 15cm heels ).
And for documentation: well you normally need both, a simple version with pictures for the users who do not want to read 100 man-pages. But then you also need a technical detailed one for weirdos like me ... otherwise I've to read the code to understand how things are working.