A note from Margaret Burgess may resolve the issue of the adjectival form of “Frye”:

 I don’t know how much Frye would care about which variant is used, but it is perhaps worth noting for the record that the term appears in the Correspondence, where Helen, writing from London on 12 October 1934, quips: “I have quite a stock of Frygian witticisms up my sleeve to chuckle over at odd moments on the ‘bus and walking down streets, and even in lectures when they’re dull” (NFHK, 1:344). Although there is obviously no way of knowing, one might speculate as to whether she thought up the term on her own, or whether it might possibly have been coined at some earlier time by Frye himself.