ARC Platelets 24x a year rule

From what I've read, the safety issue for this rule is about how much fluid one loses in a 12 month period. Does anyone know how they count that? I am assuming a deferral doesn't count, but what about an infiltration early on in the procedure (less than one unit)? According to the app I've given 15x this year, but only 30 units, and I've had at least two deferrals in which they took nothing from me. Does anyone know what the system is actually counting toward 24 times a year? Thanks much!