I'd say having the "Remove Certification" action when a certification is selected does make sense.

and an additional patch to remove the groups button from the toolbar if groups are disabled: https://invent.kde.org/pim/kleopatra/-/merge_requests/261

In T6966#189067, @ebo wrote:

This is how the upper part of the "New Group" window looks with Version 3.2.2.2405000+git~ (Gpg4win-4.3.2-beta41):

It seems that, deviating from the task description, something else was implemented. And it's not even what Andre suggested in the comments but seemingly something inspired by it.
I do not like it.
I think that the color coding of suitable certificates is a no go for a11y. And it clashes with our color marking in VSD. Which in that case is a convenience only, that info is also available in a column. Instead of a tooltip in this case.

https://invent.kde.org/pim/kleopatra/-/merge_requests/255 fixes some low-hanging bugs to make the configuration behave more as expected

We could also phrase it more like a sentence, something like

For the certificate list it might make sense to have column-specific tool tips, e.g. to give details on "not certified" in the "User IDs" column. For the fingerprint column (just to pick one example) a tool tip makes little sense.

https://invent.kde.org/pim/kleopatra/-/merge_requests/176 removed the checkbox for encrypting to others

I'd be in favor of keeping the UI and just fixing the most significant bugs it has.

can't reproduce either

In T7206#188622, @aheinecke wrote:

With the imports I also find the imported certificates tab more useful then the number. Since I think that adding full blown keylist views would be a bit of an overkill I personally would probably just use an expandable widget in the notification and work with lists of updated users ids / summary lines.

But since this also would be some custom code maybe it would be better to show a full list view of the updated certificates?