Great choice! The pebble TIR is much more suited for small Headlamp use than the reflector on the TH20 (I DC-fixed the one I gave my buddy to try to make it have a little better beam profile for the type of stuff you do with a 1AA Headlamp).
FYI what ArmyTek calls “warm” is actually 4000k so unless your preference is AngryBlue™ just expect a nice neutral white.