I don't know if you've considered this or not, but Fieltarn will bring a lab text of 'Cloak of Black Feathers' as part of "his" 75bps
https://forum.atlas-games.com/t/covenant-design-discussion/6038/164
...and while I did not precise it in the relevant post, he'll share all these lab texts with the covenant. It's based on the official version and has a 'Personal' range though, which would exclude Fiona's magical focus. But even then, with her still impressive lab total, she could re-invent this 'Personal' version in one season by using the lab text. Without experimenting. Granted, your project has the additional benefit of potentially targeting others. Oh, and also of not having to wait for Fieltarn, lol. 