Thanks for linking me here Divlaine. I believe I have a solution that works. It's hacky, but whatever. I'm in the middle of refining, but using the tip from tbeiser (and a bit from here: https://stackoverflow.com/questions/44884683/android-how-to-force-navigation-bar-to-be-visible-on-samsung-galaxy-s8 ), I used Distriqt's Application ANE to mess with the nav.
When I'm on a screen where a textfield is (forms and such), calling
Application.service.setDisplayMode( ApplicationDisplayModes.UI_NAVIGATION_HIDE );
Results in the textfield and cursors aligning properly. Which is a bit counter-intuitive since LOCKING the navbar in place actually results in textfields working properly.
Once I am out of that screen, I restore it with
Application.service.setDisplayMode( ApplicationDisplayModes.UI_NAVIGATION_VISIBLE );
As not doing so leads to some UI elements being hidden under the statusbar (basically shifting the app upward).
There's a flicker (and re-render) when I make the call to UI_NAVIGATION_HIDE, and I need to tweak this to only target the galaxy devices (or maybe just devices that mimic this functionality), but I'm glad to have the beginnings of a solution.