LadyFalcon

I tried out the Crimson arc, but had the best luck using the Peregrine Island bank mission (if you have the Safeguard Mission contact unlocked). Even soloing, x8 team size gave me 12+ sappers just from street sweeping and it only takes 2 minutes per run. Then leave mission, abandon it, and talk to Agent Hassell again to restart mission. The keybind definitely makes it easier!