First things first, @Thinder: To practice attacking the Titan, you really don’t need any of the Guardian stuff except the nanite torpedoes (which you can purchase for credits). Just slap either four EAXMCs or four AXMRs on your Python Mk II and you’re ready. You won’t be able to rack up as many credits as you would with 4 shard cannons with the AGZR mod, but you can still rack up plenty. (Here’s an example build.)
Thinder
Geeeeeezus... That's new. Now that I have transfered the material to the Carrier, I can't recover them, retransfer to the ship for unlocking the Corrosion Resistant Cargo Racks.
Writing a ticket, I don't think I'm gonna be ready for the last chapter of the Thargoid invasion any time soon...
Here’s the already confirmed ticket (out of several that were written), in case you missed it.
Also, you don’t need the anti-corrosion cargo racks for Hardened Surface Fragments, nor for any other materials required for the AGZR mod (or any other blueprint, for that matter).
(Edit: Also, you can farm Caustic Crystals at the remains of any of the already destroyed Titans.)