I think you can get industrial circuits from the mission board. But for me it takes too long.Don’t you get industrial circuits just by doing the one mission board thing where you send your leaders? I feel like I’ve gotten boatloads of materials from them. Also hunting
Also I've hunted the legendary crocodile and 1 other animal and bought specialized hunting gear. I heard you can turn some legendary animal skins in for industrial circuits but have no idea if these legendary animals respawn.
For me industrial circuits are hard to come by or maybe i'm playing the game wrong.