The list is shorter currently than I’d like it to be, will check some more first person games shortly together with adding gestures. Got somewhat shoved to the backseat when I started to experiment with gestures. Same for the related authoring UI.
With the current detection mechanism my guess would be that it should be possible to add the feature to maybe half the G3D first person games. Additional manual authoring based on shaders or buffers is thinkable and would probably be able to catch most of the other half, but would also require more work per game than the current mechanism. So no promises in that respect.
Current games with auto weapon hide:
Aliens: Colonial Marines
Black Mesa Source
Half-Life 2 and episodes
Halo MCC (tested only on the first campaign)