So let me get this straight: you used "Android developer settings access" (how did you do that, BTW?) to put on an overlay to the display that covers 80% of the screen, which doesn't support touch interface, and the way to re-enter developer settings is via an app that is under the overlay that you can't move/get to now?
The setting is called "simulate second screen". That implies it's designed for projecting that "overlay" onto a second screen, as if for cars with two displays (like a HUD as well as an infotainment panel). And I guess there's no way to attach a second screen to feed it?
As for "factory reset" on the 9" Touring head unit - have you tried the "soft reboot" hidden menus?
www.civic11forum.com
I don't see one for "system reset" there (the whole point of that thread was to find out how to reboot the infotainment unit WITHOUT doing a full, hard factory reset), but maybe a soft reset would help you here, or you could try some of the other options on those hidden menus.
The setting is called "simulate second screen". That implies it's designed for projecting that "overlay" onto a second screen, as if for cars with two displays (like a HUD as well as an infotainment panel). And I guess there's no way to attach a second screen to feed it?
As for "factory reset" on the 9" Touring head unit - have you tried the "soft reboot" hidden menus?

How to Reboot 9" Head Unit Infotainment
There is a way, its just hella annoying access it. 1 Hold home+power+previous 2 Tap detailed information and settings 3 Hold back+power+previous 4 Tap system reboot I find this can help with laggyness.
I don't see one for "system reset" there (the whole point of that thread was to find out how to reboot the infotainment unit WITHOUT doing a full, hard factory reset), but maybe a soft reset would help you here, or you could try some of the other options on those hidden menus.