Still new to the MilesTag arsenal and found the thread here
It basically adds in functionality for a secondary add-on device that shocks or buzzes the player to let them know they were hit. They don't show prototypes, but it made me think about how you could add this in and make it work. My idea wouldn't be for a shock, but a vibrating watch or chest piece that works like the rumble packs in console controllers.
Basically, I would add a selector switch, that works much like a MOSFET and attach in parallel to the Hit LED + line. Since these are often connected to vests and other tactical gear, adding a single line to your wrist/arm shouldn't be a huge deal.
I attached a poor drawing of what I think could work. Basically, when the LED is on, the vibrator is running. I integrated their idea for a separate battery power for the addon. This could be easily made modular by just putting a quick disconnect available at any local hardware store.
Something like this
would work for the vibration motor.
The reason that this caught my interest is because one of the guys who is building a MT Core unit with me is interested in possibly making something like this.