Joe
I used to have the E-F raise. It's a toss-up for me because sometimes I liked to use 1) the descending line F-E-Eb on string 6, and 2) the F-G-A triad on strings 6-5-4.
However, I can get the same triad 2 frets back using strings 5-4-3 with the 2nd string lower lever.
The 5th string whole tone lower G-F was suggested to me by both Paul Franklin and Jim Loessberg, who to me are like E.F. Hutton... when they talk, I listen.

And since I had a vertical on C6 I wasn't using, I slapped it on there.
It's useful to me, right now, for a full dominant 7th with pedal 6, root tone in the middle as well. Also for a #9 chord with pedal 5, and a major 7th half-tone interval with string 6 (E-F), an augmented with pedal 8, as well as a cool descending (or ascending) run chromatically from string 1 (D), string 3 (Db-C-B), string 4 (Bb-A-Ab), string 5 (G-Gb-F), and string 6 (E-Eb).
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