Yes they should!

Felix teaches sorcery when they ask him to and they advise Naoh and try to soothe his situation without being too suspicious.

They are in general not tutoring on sorcery-gifts in general. This is partly because the risk of something inconvenient like "magic detection that detects metamancers" is real and partially because he doesn't really have a safe and efficient way to teach it to a lot of people. However, if Kaede wants to Felix can walk him through the lifeforce exercises - getting a grasp of teaching it could be useful in the future.

He works on the two sorcery books.

Naoh eventually asks, and is allowed to send letters to his family, as long as someone else gets to read those letters and make sure they don't contain any extraneous information, for his own and his kingdom's security, of course. Kaede does want to learn that, though, and is in general delighted by watching Felix teach things. He finds it "very hot."

And one evening, after some editing and making sure it all makes sense, Felix is done with the two books. "Well."

"I guess this is as good as it's gonna get. How long do you need to drop the book?"

"I can probably go tomorrow, after dinner. Leave an illusion here, stronger than theirs, and fly somewhere."

Nod. "Have you picked a place yet?"

"Yeah—" He grabs a map and shows Felix a little city in Laokab, near the ocean.

Felix nods. "Any particular reason you picked this town?"

"Pretty far from here but has a big museum and a nice library, for a Laokaban town, mages like stopping by sometimes, basically guaranteed someone will find the book soon."

"Good." Kiss.

And they proceed to add the finishing touches and then are all set.

They don't present it to the scholars yet.

The following evening, she kisses Felix, makes herself undetectable, goes through the wall and under the wards, and flies extremely quickly.

It's honestly exhilarating to fly that fast. To have enough mana to fly that fast. She's left most of her mana in a battery artefact at home, and another chunk in another battery artefact inside her pocket. It won't be invisible to other metamancers, but if they're not actively looking for it they won't really find it.

And soon she reaches the library she had in mind.

The library is full of people that don't spare her a second glance and she is likely to do the same. Given that they're in a library the atmosphere is quiet but there is a group quietly chatting over there blocking Kaede's line of sight from a quiet nook where a girl is reading.

Temperance Greennoon had a bewildering week when she suddenly noticed that nearly everything around her had acquired magical properties that are unlike the kinds of magic she knows. She stared at things until she literally couldn't stand it anymore and decided to do the more mundane variety of research. And all she could glean from squinting is that the magical properties have something to do with draining living beings of their whatever makes things alive (which was a concerning discovery).

And here's this girl with a veritably enormous quantity of these things.

Yes, there she is. Temperance literally drops her book. She manages to pick it up without looking away.

That is a lot of "makes-people-alive-thing" (Temperance hasn't considered calling it by a specific name yet, she could hardly talk about it with anyone). She notices what looked like variance between people, but that is several orders of magnitude greater than everyone else.

After too long of a pause, Temperance starts observing instead of staring. What the girl is doing?

She is going to the back of the library where Temperance can't see her anymore!

Well, a little spying is justified in Temperance's opinion. She casts something that will allow her to see the other girl from a distance and regardless of obstacles.

The other girl is surreptitiously depositing a book in a place calculated to annoy the librarian a lot.

...and that's it. She seems satisfied, and starts making her way out again.

Moment of indecision. She could check the book right away or talk to the person with absurdly high power...

It really shouldn't be so hard to decide. That girl could be dangerous-

But she might know something too-

But the book-

Temperance settles on leaving a small magical mark on the book and then following the girl.

The girl weaves through the sparsely populated evening in the direction of...

...well, out of town.

Mysterious girl with mysterious traits leaves (presumably mysterious) book in a town and then just leaves?

At times like this, Temperance really wished she could just... tell people. Temperance makes herself undetectable and then follows.

And when mysterious girl is far enough away from the town she takes flight.

...she is rather fast.

Well, Temperance follows.

Well, she tries, but when she attempts a mid-flight change on her blessing she is distracted by a bug colliding with her face and becomes suddenly affected by things like light, sound and gravity in normal ways.

Which is to say she is visible, screaming and falling.

And now she is floating again, and the mysterious girl is in front of her. "You ruined my entrance," she says, pouting.

"Uh... I didn't mean to," Temperance says, because screaming is probably not useful.

"Yes, I know," she sighs. "I'm gonna land us so we don't waste mana needlessly."

And she starts slowly descending.