That gadget slot has among others:
Speed loader, Light foot, HH and reactive armor.
I just made 3 loadouts. 1 for LF, 1 for HH, and 1 for RA.
All that's left is to try them out. See if i notice an actual difference.
Okay, so i got rid of the HH one. Seemed useless.
I got two loadouts left. 1 with LF and one with RA.
LF for against lower lvls, RA for when i'm up against higher lvls.