I guess the most easiest way has already been suggested by Lumoti: Get a case with bulkier sides and try cutting out the cases’ button for the Essential Key.
Other than that, I can only suggest making your frustration official by sending in feedback via the official channel:
Open the settings on your (3a), search for feedback and tap on the suggested link. Then follow the instructions to get to the feedback form.
I can only imagine, the more (3a) users are sending in their negative feedback, the more Nothing might be willing to introduce further options regarding the Essential Key.