Spenser's Shepheard's Calendar comes ready supplied with scholia, supposedly written by one 'E.K.' This used to be critical debate about the identity of this individual, which is still not known for sure: ('In spite of the fact that E. K.'s initials are attached to the comments on the Shepheards Calender and that Webbe considered him a high authority in critical matters, his contemporaries have not told us who he was', says C R Baskerville). Some critics think him a pseudonym for Spenser himself (Raymond Jenkins, "Who is E. K.?" Shakespeare Association Bulletin for instance), though C S Lewis thinks this unlikely as 'E.K.' and Spenser profess very different tastes. Still, it's possible for an alter-ego to have alter-tastes, I'd say. Louise Schleiner ('Spenser's “E. K.” as Edmund Kent (Kenned/of Kent): Kyth (Couth), Kissed, and Kunning-Conning', English Literary Renaissance 20:3 (1990), 374–407) ingeniously interprets the letters. Here's a passing thought: might 'E.K.' mean what it says? That is, taking the 'e' as long, might it not be saying 'eke' (OED lists the following early spellings: ec, ek, eek heke. eke, eik, eake)? That, in other words, the poem was written by Spenser and the notes also?
Just a thought.