Oh, so the utility is universal, great! Thanks!
All Fire Tablet wall mounts I’ve seen so far are a challenge to choose: “Sturdy, Cheap, Good-looking - pick 1 of 3” 
Hoped you found something! Yeah I do remember the printed case story, and yes, its price kind of beats the purpose 
For now, QI with magnets seem to be the only universal way to go. Also, Sugru handmade mount fits some places, as mentioned by JDRoberts here: Dashboard Theming (Custom CSS) and Mounting Hardware Ideas - #2090 by JDRoberts
Please do share when you finish the install, - the project of 9 tablets deserves to be highlighted.