Hello Eli,

I tried to fullfill the requests on Emacs-devel about overwriting a
register with no confirmation, this will happen when
register-use-preview is nil or 'never.  Even with this configuration we
still have filtering when preview buffer is visible and in any case we
have defaults with M-n available when the register command is of type
'set'.

So now to resume the situation:

1) register-use-preview == t

We have a register-preview buffer with navigation and selected register
highlighted, when the register is selected we have to press RET to do
the action on this register.  Defaults are provided for registers of
type set.  Registers are filtered depending on the command used.

2) register-use-preview == nil

We have a register-preview buffer with no navigation and no
highlighting.  No confirmation with RET is requested, as soon as you
enter the register name, minibuffer is exited immediately.  Filtering
and defaults for register of type set are still provided.

3) register-use-preview == 'never

Same behavior as 2) but there is no preview buffer at all, however if
user type C-h, a preview buffer is provided behaving like 1) i.e. RET is
requested when selecting a register.

4) For registers which are key sequence e.g. C-a

For entering manually in minibuffer such a register one have to hit C-d
C-a.  This is now the only thing that differ from Emacs-29.1 behavior.

Let me know if I can push this patch.

I think all this is a real improvement for Emacs despite the several
complaints we had recently, however if all the arrangements I did are
not enough, we could add a new variable register-read-preview-function
and reinstall the old code exactly as it was (it's easy, let me know if
you want this I will provide the patch).

Thanks.

-- 
Thierry