Haven't seen a lot of examples of boards that implement the GA-FC, so here's the one I just put together! (Also posted in r/guitarpedals) : r/BossKatana
Amazon.com: Roland GA-FC Foot Controller for GA-112 and GA-212 : Musical Instruments
Guitar Pedal X - GPX Blog - Boss's new GA-FC-EX Foot Controller Massively Expands on the Control Capabilities for Katana Amps
BOSS GA-FC Guitar Combo Foot Controller | Guitar Center
The GA-FC: Unlocking Performance Potential with Your Amp
GA-FC EX : FUNCTION EXPLAINED & MORE – Roland Corporation
The BOSS GA FC EX: An Amazing 2022 Overhaul For Katana Users!
Unlock The Boss Katana - GAFC EX - Free Preset Pack. - YouTube