Per-file Shift Lock Mode

[Ken Haase <KWH at MIT-AI>]

In ZWEI in System 79.18, ZMail 40.7, Remote-File 2.0, LMFILE-Remote 5.2,
microcode 849, 60.45Hz, on Lisp Machine Nine:

Is their a way to set Electric Shift Lock Mode in the mode line?  I know
about ZWEI:ELECTRIC-SHIFT-LOCK-MODE-IF-APPROPRIATE (or whatever), but I
would like it to be on a per-file basis; If it is implemented, Update
Mode Line doesn't do the right thing, and if it is not, how hard would
it be to put in?  It seems inconsistent that Font Lock Mode is on a
per-file basis while Shift Lock Mode isn't.