She’s going to remember that.
But right more importantly…

She nods, she might not know his reasons for it, but she knows how to keep her word.
“My lips are sealed, I’ll keep calling you Corvus-san too until you tell me otherwise” she knows names are important. That much is clear to her.

Hannei smiles, apparently not too upset about not being understood. “I have been told I’m a bit weird” you don’t have to be so casual about that. But she looks more thoughtful a moment later.
“That’s… a good point. Just asking you to trust I wouldn’t lie feels a bit weak” so something that can be confirmed by an outside source?
“… well I suppose you could ask my Akechi-Kun to confirm my memory, though if you don’t want to do that…” she’d get if he’s trying to avoid other Akechi for his own reasons…. “…maybe you could ask Fenrir?” …ok maybe getting confirmation from someone’s persona is a bit of a stretch.
But she made this offer seriously, she wants to take his concern seriously too.