On a hunch, I did some tweaking in settings (settings vary from person to person so that was possibly the reason). It seems that the setting "Voice Messages in Battle" affects this mod.
"Commander" setting (as you can see in my last post) is the reason that the hitmarker sound doesn't work. Changing it back to "Standard" fixed the mod, in replays anyway. Update: This fix works in real-time battles too.
Is there anyway to allow the mod to work in "Commander" setting as well?