There may be examples in my older hymnals too, but I wasn't able to find any (this seems to be something that shows up more in modern music).
“Hallelujah, Praise Jehovah” (1899) has doubled Fa's in the treble and bass clefs at the beginning of bar 9. Here’s a scan from a hymnal printed in 1911. The Fa is reversed in the treble clef.
Whatever the consensus on usage may be, I would like to be able to orient doubled Fas either way, according to the usage shown in these examples.
Yes, that sounds reasonable.
David F.