apply a global modifier per-user when an item is held/worn

I'm gonna have to sit on this for a bit while i figure out the best way to achieve this. The point in the current XP pipeline where worn/held items are factored in doesn't lend itself to global modification. However, I believe a refactor of this system might be beneficial to performance at which point I could redesign the system to incorporate this. It does seem sensible to me that an item could give a global boost. So it's just a matter of making that a reality.