First run on guiding bridge gave me 2.5k second gave me 930 also less scrap from breaking enemies

Just tried the guiding Bridge method someone mentioned below and i think i'm getting diminishing returns there, after a couple runs its only giving me a few hundred

Wabasi: Odd, I didn't notice any diminishing returns myself... must have been a stealth patch. Or maybe it's because i was getting hit by the enemies about once every three runs lol.
Lentinant: I'll have to check that spot (uninstalled after 100% due to potato specs), but if it works i'll edit things.

I'm not sure if this was always in place or was patched recently but after one cycle I could notice that the game would nerf the amount of materials I was receiving. To solve this I did both this route + the "Before the guiding bridge" lentinant mentioned in the comments. As long as you move to a different area it seems to reset the nerfed mat gain. Was able to get 70-80k in about 35 minutes or so.

"Before the Guiding Bridge" point in the Cental Stratum - Steel District, go right, drop down, Garm skill down on the right of U shaped platform to get to the bottom fast. Climb to the wall on the right, charge dash left, you are in the room with some containers that give up to 2500 materials or so. With properly placed wall clinging, you can break them by flying into them. The entire process takes like 15 seconds.

Works good

This is the best material farm spot I could find while grinding for the relic/totem achievements, if someone knows about a better spot, I'll update the guide.