We need to be more clear on what "material theme" is.
What I posted now is -- the app *emulating* the Android 5 Material theme when running on 4.0+ (including 5.).
It does not use the *system* Material theme in Android 5 (since it's not there on devices with 4.0, 4.0.3, 4.1, 4.2, 4.3, 4.4).
When running on Android 5, I could "inherit" my new theme from the *system* Material theme (not from the 4.* "Holo" theme).
This would give a new look to things like checkboxes, radio buttons, etc., and maybe some other thing I don't know yet.
However -- this *system* Material theme does not support "action bar icons along the bottom", and it was just now marked as "working as intended / won't fix".
What this means in practical terms -- inheriting my new theme from the system level Material theme -- I'd *have* to use the Giant Button Floating in Space to give the user easy access to at least one command (and two more in the top bar... except it's one, just one icon, on a 480*800 screen... used to be two).
The older themes -- light, dark, dark + dark messages -- are not affected, I'm going to keep using the 4.* "holo" theme as their base.
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I filed the original bug against the "L preview" over three months ago (July 17). It should have been possible to communicate this "won't fix" somewhere along the line. I guess better late than never, anyway.