New SP player — which frames should I prioritize and how do you approach build optimization?

Hey everyone! Relatively new player here, slowly working my way through Steel Path. Looking for community advice on frame prioritization and build philosophy.

Frames I've already invested in (SP-ready or close to it):

Nekros Prime, Wukong Prime (main), Mag Prime, Caliban Prime, Khora Prime, Xaku Prime, Volt Prime, Sevagoth Prime, Yareli Prime.

Frames I own but haven't invested in yet:

Zephyr Prime, Ash Prime, Chroma Prime, Wisp Prime, Protea Prime, Oraxia, Oberon Prime, Nova Prime, Nezha Prime, Octavia Prime, Lavos, Harrow Prime, Gauss Prime, Excalibur Umbra, Frost Prime.

My questions:

Which uninvested frames would you prioritize for SP and Deep Archimedea, and why?

My current philosophy is to go frame by frame — I don't move on until the current one is fully optimized (right forma, mods, arcanes, shards). For example, Lavos has a Mecha build that needs harder-to-get mods, so I'd farm everything before moving on. Is this a good approach or would you do it differently?

I have some Helminth abilities available and plat to invest, but I try to be smart about resource allocation. Would love to hear how veteran players approached this stage. Thanks!