Since the Ctrl-Shift-L keyboard shortcut works well for autofilling login information, why not also implement a hotkey for triggering autofill of card information (and perhaps also a different hotkey for autofilling identities)? As with the login hotkey, repeated use of the key would cycle through the available cards (or perhaps some additional features could be implemented to facilitate autofill when a large number of cards are available).
Autofill on page load should also be considered. Perhaps a list of URIs for which autofill would be triggered (and/or prevented) could be part of the configuration of each card item.
Thank you, @Kenmoffat . If you have any votes left to give, perhaps you may consider officially voting for this feature request (using the vote button in the upper left corner).
The implementation of keyboard shortcuts for autofilling of credit cards and identities are now needed more urgently, since the newest UI redesign pushes many card and identity items off the screen in the Tab view, requiring extra mouse manipulations to scroll the view before one can select an item to autofill.
I have also identified the following Feature Request threads, which are asking for essentially the same functionality:
