Atmos Height Speaker Height...How High?


My ceiling is 22 feet high. I’ve read that the ideal height of an Atmos height speaker is 8-10 feet.
Is there any benefit to go to 15 or 20 feet high for the height speakers?
I'm upgrading to a processor with Atmos soon.
This is my room: https://systems.audiogon.com/systems/876
128x128mitch4t
Great Room and some really nice 2 channel gear.  
Question: Have you ever seen ceiling mounted speakers in a movie theater?  They mount on the walls up high but never that high.  I don't see a system correcting for something so far out of the "norm".  Many Atmos speakers use reflections to get the height speaker sound-upwards firing little speakers.  Could you hang speakers on a wire from your ceiling on 12 foot long wires-you could actually put them in light fixtures just like your hanging lights.  It would look awesome.  This is only for sound effects anyway.
Processors have Delay built in for all channels. Some set the distance automatically in the Room Calibration/Correction Software, but I have found those to not be accurate and generally works better to manually set the Delays.

This PDF may help guide you in your venture for placement:

https://www.dolby.com/siteassets/technologies/dolby-atmos/atmos-installation-guidelines-121318_r3.1.pdf