Waiving event fees with Integrated Event Accounting

What is the best way to handle fee waivers when using Integrated Event Accounting and RSVP’s? Our troop is moving toward using mandatory IEA for all of our fee activities, but we waive those fees for certain individuals (Scoutmaster, etc) and would like the flexibility to waive them for others on an as-needed basis. Does TT allow us to waive fees for RSVP’d attendees?