That's pretty imaginative using the antenna housing.
I use this one myself. http://www.impconcepts.com/impstore/index.php?route=product/product...
It's quick to disconnect as one part stays attached to the radio and the other part stays attached to your tablet.
Like it, Torque on the housing might scare me. I made a few zillion of these things for Tango and my nexus 5. Used the back rail to mount the frame to it.
The housing is fine the little pole piece has to be printed at around 40% though. Maybe a hoop for the antenna somewhere.