Eli Zaretskii <eliz@gnu.org> writes:

Anyway, I think making the cursor change from a mode hook is a better
solution.

As has been mentioned, the problem is that not every scenario is covered
by hooks, while the PCH is a potentially universal solution which can
check arbitrary conditions. But if hooks work sufficiently well for most
scenarios, then why not.

If there are cases that this indication supports but there's no mode
hook for them, let's discuss those cases one by one and see how to
solve them. I see overwrite-mode, read-only-mode, and input-method
activation, all of which have hooks, AFAIR.

But the problem with using hooks is that modes sometimes defines a
specific name for hook or use different hooks for that, for example
overwrite-mode only defines overwrite-mode-hook, however input-method
defines input-method-activate-hook and input-method-deactivate-hook or
mark/region have activate-mark-hook and deactivate-mark-hook.