I think these could be usable
Amaryllis- I had a fanfic character named this, and florals seem to be rising
Briseis- I have a student named Briceida, and Briseida is in the submitted list and is similar, so yes.
Hildegard- maybe just
Hilda/
HildeElfreda- maybe
Alfreda to honor an
Alfredo
Amadeus- hipster classical fan parents? With the movie
Amadeus and wasn't there a song 'Rock me
Amadeus', so it hasn't totally disappeared from being known.
Dragomir- more use in Slavic countries, but why not
Thaddeus- again, the hipster names
Wulfstan- if someone wants to find an animal name that isn't just an animal name, maybe