The github repo mentioned this wiki article for multiplayer performance tweaks. Did you run through this list and make the recommended changes?

https://satisfactory.wiki.gg/wiki/Multiplayer#Engine.ini

+1 for Brozime. Great content creator and all of his videos for warframes and weapons usually have a budget-build more accessible to new players. He does a free-to-play run almost yearly and he’s due for another one soon since some minor things have changed.

Watch his free-to-play run and join a clan to help get up to speed.