draft-config-exec conundrums...

Greets All:

I've been perusing the info pages and unclear about these bits from
7.1.4 Dynamic Modification of Messages:

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   If you don't want to apply 'wl-draft-config-alist' when
'wl-draft-send-and-exit' or 'wl-draft-send' is invoked, do the
following:

     (remove-hook 'wl-draft-send-hook 'wl-draft-config-exec)

   If you want to apply 'wl-draft-config-alist' when a draft buffer is
prepared, do the following:

     (add-hook 'wl-mail-setup-hook 'wl-draft-config-exec)

   If you want to apply 'wl-draft-config-alist' when you re-edit a mail
from summary mode by typing 'E'('wl-summary-reedit'), do the following:

     (add-hook 'wl-draft-reedit-hook 'wl-draft-config-exec)

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Not a lisp coder and as far as I can discern as long as you're calling
the wl-mail-setup-hook not much else there matters.  Indeed, does not
seem that the reedit-hook does anything.

Japanese is not my first language (can count on both hands the
words I can even still remember).  English is not the doc authors first
language either and result in some terse, not quite clear, at least to
me, explanations.  Would somebody with a clue or two please elaborate
just exactly what the above actually DO and maybe give an example or
two of where/when they may be useful?  Just trying to grok the docs
here.

TIA-- Ken