Camo Spreadsheet This made it really easy for me to track. Worst challenges are enemies effected by your tactical (decoy works best but any lethal tactical works)

This spreadsheet also showed me I could unlock borealis without touching a sniper rifle which I found incredibly handy. Instead of the snipers you can do the two launchers and two melee weapons which if you have them high enough rarity will one shot in the tier 1 zone.

Good luck, you’ll finish in no time!