can undo unamalgamation be turned off reliably and completely?

[Samuel Wales <samologist@gmail.com>]

this has been a struggle for 20+ years.  maybe longer..

emacs hardcodes 20 characters [as of emacs 25-ish, commands also] for
amalgamation.  (hardcoding?)

i never want this.  no matter what.  (except, if some internal code
relies on it, then i want that to not break.)

what can i do to get rid of undo amalgamation so that i never have to
deal with this issue again?  i want an undo boundary after every
character and command that i interactively run.  as normal, just like
emacs would be without amalgamation.

the many things i have tried have been unsatisfactory.  emacs changes
under me to ignore undo-boundary [bug report filed, fixed, thanks], or
it adds new commands that bunch up, or it does not allow checking
whether i interactivity called the command.

i use undo-tree.

i use emacs 25.

thank you.


p.s.  if possible, please include me in addition to the mailing list
address, so your reply doesn't get lost in a folder.  thank you.