Hildegard and quilismas

I've set in Gregorio a "Solesmesified" edition of Hildegard of Bingen's "O magne Pater", using 3 different editions plus the Riesenkodex facsimile. My question has to do with quilismas. In the chant we all know and love, one always sees the quilisma as the center notes of a scandicus; I don't recall ever seeing it in any other context, which is handy when you're reading from the Liber Brevior and aren't sure whether in fact it IS a quilisma. But in Hildegard it's different: in this piece at least, a common figure is to have a punctum followed by a torculus beginning on the same pitch, and that first pitch is a quilisma followed by a third, eg:

g g b a
p q

Is this a German "chant dialect" thing? I know that German sources often have a minor 3rd instead of a step, going into a cadence. Or is it a specifically "Hildegardian" feature? I'm tempted to Solesmize these figures (move the quilismas up a step), but I need some historical justification.

And how to perform this? The usual lengthen-the-first-note thing seems pointless, since it's already lengthened by the quilisma. One could sing it as an ornament, but in the recordings I've listen to, people seem to warble anywhere BUT at a quilisma. And what's with scholarly editions not considering the quilisma to be valuable information in spite of it being clear as day in the facsimile?