I would lean to 'genera - szee - own', etc. Of course, there are many instances where 'genera - shun' is necessary because of the syllabifica - szee - own' won't work - probably in most instances.
Good question! in McGee's _Singing Early Music_, David Klausner gives "habitacioun" as [habItaSI*U:n] (sorry for no small caps in my IPA) but says elsewhere (not in this specific context) that "t stays t".
I've generally heard "si-on", and that works well enough when you need it in 2 syllables. It's worship, not musicology. I mean, you aren't going to use Tudor English for the rest of it, are you?
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