This method is called converting. ( only casual) So their is organic polymer and normal polymer. (Organic is a substitute for normal polymer) now obviously you can get a lot from killing Kairukus or using a snail. But theirs a catch to using organic vs normal polymer, organic spoils and comes in stacks of 10, normal does not spoil and comes in stacks of 5000 (mobile). Fabricators can only hold 70 slots. Organic can not be used for advanced blueprints ( Mastercraft/ascendant) how the trick work is this. Get a pretty big that uses polymer. (Vault,air conditioner, or elevator things,) take out all normal polymer and keep organic. Make the structure and then destroy it the organic polymer comes back as normal polymer. Rinse and repeat as many times as you want. thank you for reading and respond me at @Blackout
(On Rag) Go to the volcano, riding a wyvern, and have a all weight argy on follow. Make sure the argy is on passive. Kill mantis, then harvest them with the wyvern, and load all the poly onto the argy because of the weight reduction. I got thousands of poly in about half an hour using this. If the argy has about 1000-2000 weight you can go for about an hour and come back with thousands of poly.
Go on abberation, tame a high lvl spino, and start killing karkinos’s. On 2x u get like 80 to 100 organic polymer from each. Remember get a HIGH lvl spino cuz whenever there one karkinos, there more nearby.