Each of the currently available (four) frames has its own set of hunting challenges, which are essentially various destroy tasks. I decided to start this way later than I should have, and have already completed many of the challenges. I started with what I had currently available, and with help from others, will hopefully make this a complete list.
You will also be required to complete these if collecting all Blueprints, as each challenge will reward Blueprints the first time around. After completing all challenges, you can complete them again, but will only receive crafting materials.
K-9 (6 Challenges):• Destroy 5 Enemy Corebots with Blue Lethal Attacks: Natural progression, any enemy Corebot will do, Lethal is used by pressing
• Destroy 10 Red K-9s: Natural progression
• Destroy 10 Blue K-9s: Natural progression
• Destroy 10 Red K-9s and 10 Blue K-9s: Natural progression
• Instant Extract 10 K-9 Cores: Natural progression
• Destroy 5 Purple K-9s with a K-9: The Cradle, beside House of Steel dungeon entrance
SP-DR (7 Challenges):• Get a 15x Combo Score: See solution for Master Juggler (achieve combo of 40) for best spots
• Destroy 10 Enemy Corebots with Yellow Lethal Attacks: Natural progression, any enemy Corebot will do, Lethal is used by pressing
• Destroy 10 Red SP-DRs: Natural progression
• Instant Extract 5 SP-DR Cores: Natural progression; sometimes you can get this on one of the Red SP-DRs outside of Joule's Crawler.
• Destroy 10 Blue and 10 yellow SP-DRs: Natural progression
• Destroy 10 Rare SP-DRs: [What's a rare SP-DR?] Fast travel to The Cradle (beside House of Steel). Exit the pipe going left, into the open, and an Orange SP-DR will spawn
• Destroy 5 Purple SP-DRs using a SP-DR: Fast travel to Kai's Crawler (The Cradle), and head up the path towards the North-West area
AP-3 (7 Challenges):• Extract 5 AP-3 Cores: Natural Progression
• Destroy 10 Blue AP-3s: Natural Progression
• Destroy 10 Red AP-3s with Red Lethal Attacks: Natural progression, any enemy Corebot will do, Lethal is used by pressing
• Destroy 10 Blue AP-3s: Natural progression
• Destroy 15 Blue AP-3s and 15 Yellow AP-3s: If I recall correctly, House of Steel provided each of these colours in the first room (please correct me if wrong)
• Instant Extract 10 AP-3 Cores: First room in House of Steel. Four AP-3s will spawn, and you can instant extract one of them. Then return to crawler and come back.
• Destroy 5 green AP-3s using an AP-3: Base of tower in The Cradle after first getting Seth, near Kai's Crawler
FL1-R (7 Challenges):• Destroy 5 FL1-Rs: Natural progression
• Destroy 5 FL1-Rs with Lethal Attacks: Natural progression, any enemy Corebot and any Lethal will do, Lethal is used by pressing
• Destroy 5 Yellow FL1-Rs: Acid Marsh dungeon
• Instant Extract 5 FL1-R Cores: Natural progression, I found many opportunities for this during the tower climb
• Destroy 5 FL1-Rs with Lethal Attacks (confirmed): Natural progression, any enemy Corebot and any Lethal will do, Lethal is used by pressing
• Destroy 5 Blue FL1-Rs and 20 Yellow FL1-Rs: Acid Marsh dungeon
• Destroy 5 Purple FL1-Rs using a FL1-R: In The Warren, next to net of respawning Red Corebytes
The Acid Marsh dungeon is a good place for all of the FL1-R challenges except the last one.
I'll continue to update as new information is found. Thanks (and credit) to Karachi King, Gizmo2k, Calex dEUS, skylinesend, Cuthred and JonoTheLad for their input thus far.