Like suggested as a comment for https://dev.gnupg.org/T5903, I'd wish to have a RMB (right mouse button) context menu for the list of certificates to refresh just the current one. There exists a menu entry to refresh all keys, but there may be reasons not to want that.
The feature cited basically implements the same, but at a "higher UI level" (i.e.: one level deeper in the structure).
I think the advantage of my proposal is that one might even multi-select keys and then use the context menu to refresh just those keys.
For the German UI the context menu looks like this (in 4.2.0):