A repetition of the reminding (?) 
before f
1 may seem to be superfluous, cf. the version of GE3; however, in the main text, we preserve this mark due to the f note featured in the chords in the L.H. Moreover, if we take into account the entry in FEH, i.e. a 
before the 1st grace note in the bar, the discussed takes on different meaning, becoming a mark restoring f1.
Compare the passage in the sources »
category imprint: Differences between sources
issues: GE revisions, Cautionary accidentals
notation: Pitch