When having downloaded several ".asc" keys from some internet site, and you want to import them, one way is to open the file explorer and double-click on them.
A dialog appears asking to confirm the import, and offering to sign the key (after checking it).
However when the dialog windows is behind the explorer windows, the user may not notice it, and instead be wondering why nothing happens (or whether something did happen).
Probably the user double-clicks the same file again, but this time nothing would really happen (as GPG4WIN is blocked by the dialog already open).
Even more: Not noticing the dialog window, clicking on the Kleopatra main windows may trigger an "application is not responding message". If then the user decides to terminate Kleopatra, then restarting it, things even become worse as Kleopatra will complain that it could not connect to the background service, suggesting that the installation might be corrupt and should be repaired.
So it might be a good idea to open the key import dialog in the foreground when a key will be imported via file association (assuming that use case can be detected).
When the key import is triggered from Kleopatra directly this should not be an issue as the dialog should be visible in any case.