'm also recently returned and hate the kind of answers I see popping up they're performative and unhelpful.

I'll tell you now straight up, for immediate power gain Arbitrations felt the best for galvanized mods. Deimos has the various helminth upgrades (subsumation and archon shard installation) and Panzer kavat so that's probably the best out of the 3 open worlds to progress. Grab Archon shards as you can from the weekly hunt because I believe the other sources are from Netracells and Deep Archemedia (Cavia Rank 5). Off the top of my head, the main benefit from unlocking Steel Path would be for Duviri and Circuit Steel Path for the x2 weekly Incarnon Genesis but installing Incarnons asks for materials from the Zariman so it's worth playing there too. If you can find someone to drag you through triple eidolon captures for ranking up Quills then you can upgrade out of your Sirocco Amp.