Here’s my similar approach. The frame is custom made and mounted onto the tablet. The tablet is clipped into a modified wall mount built from an old case. The frame and tablet can be pulled off of the wall together as a remote control panel. I used this Aukey charger because it was the slimmest I could find.
Aukey Qi Wireless Charging Pad for all Qi-Enabled Devices https://www.amazon.com/dp/B019WEURSY/ref=cm_sw_r_cp_apa_sqzJxbF3RW1AD
Now, who can give me some guidance on how to force my tiles to be centered on the screen? Is there some way to force a margin?