Factoring in how long it would take her to spit out the symbolic representation of the spells in the first place... well, it doesn't sound very much like it to her but she's not sure of the exact opportunity cost.
Annnnd Asgardian lessons, delivered with Allspeak off. She just sort of blitzes through them, assuming people will stop her if they have questions.
A week later by decree of the King everyone in the city should be sure they're fluent in Quenya, Thindarin, Mannish and Asgardian. This is of endless amusement to the girls on Loki's list. "I'd call it an abuse of power," one of them says, "but it's not even that, really, it's just a very very different set of strategic priorities than anyone else."
Fëanor is back. He consults with Curufinwë on the armor question and says that he expects it can't be done at all but that he can at least think of a way to check all the possible approaches in parallel in a month's time. He speaks Asgardian with her. He has retroactive eidetic memory with no time limitations but, as expected, it doesn't call back books from Loki's world.
She still really likes having an eidetic memory for everything since she landed, but it is sort of conspicuously gappy in her case. Alas.
Can they have tiny-cuts-healing to see if there's any way to implement it that's not in a person's mind? Can she recite any Asgardian music or poetry? Huan's potentially willing to go live on a settlement of Men if she's eager to start moving on that. Fëanor being around means a flurry of activities.
She prints out the spell chunk in her symbolic alphabet. She can recite a few epic poems (they are about wars) and sing a few songs (many of them lewd). She had been assuming Huan was stuck here, and anyway Himring being without a Maia doesn't sound like an unambiguous improvement.
With a ring of true seeing she'd be comfortable holding a city on her own against Maiar. (Melkor she's hoping will stay holed up.) "He can't be unobtrusive or he won't bother?"
"Yeah. Hopefully he'll wait until I can pop a cityful of people too."
"In Formenos he brought the creature he'd travelled with from beyond the Void, and she drowned the area in impenetrable magical darkness, and then he told the walls to fall down and walked through the streets crumbling everything he touched and sought out my father, killed him, sought out the Silmarils, took them, destroyed everything else in the house with at least some targeting - valuable things were destroyed beyond generally crushing the place to rubble - and left in probably less than three minutes."
"Yeaaaaaah that fight's going to have to wait until I have extradimensional goodies."