Guess what the latest update brought? The feature you requested has been partially implemented. We had the option to Disable Cards for a while, but the latest update added the Suspend feature.
Click any of those 2 buttons (
Disable this flashcard -non-searchable & non-trackable, as far as I know - and
Suspend all Cards in X Document), depending on the option you need (albeit it doesn’t seem to be what you are asking for):
You can however Suspend individual Cards - including Image Occlusions - from a Document by typing
/suspend or by tagging the Card with the
Suspend Cards PowerUp:
To find the Suspended Cards, search for the Suspend Cards PowerUp, then click its bullet to Zoom into the Rem. Example: