On 27 Aug 2019, Juri Linkov wrote:
>`M-.' and `C-M-.' are good keys for pulling text
>into the minibuffer, as well as into a search string,
>so let's reserve them for the text pulling feature.
>
>> For `isearch-yank-until-char', I'm not partial
>> to any particular key.  I'm just partial to not
>> using `C-M-c' for that command.
>
>Then for `isearch-yank-until-char' let's use `C-M-z'
>with mnemonics pointing to its similarity with `M-z'
>(zap-to-char).

I like that.  Revised patch attached.