SW 0.9X Coma Corrector--Visual Use w/Low Power Ultrawides?

[Phil Creed]

I am getting a used Paracorr-Type 1 to correct for coma in my 8" f/4.9.  I notice coma even with my 7XW, but it's quite tame at that point.  By the time I get to the 14mm Delos, yeah, it's definitely there.  My f/4.9 is fast, but it's not screaming, face-peeling, old-school-Metallica screaming fast, so I got a used Paracorr Type 1.

One of the reasons I bought the scope was for a combo of portability, aperture and quasi-RFT capability.  Not what I'd call a true widefield scope, but I can squeeze a 2-1/2 deg TFOV in it with the 30ES-82.

That is, if the 30ES-82 isn't barlowed in any way.  The Paracorr has a mild 1.15X barlowing effect, which in combination with the 43mm field stop of the 30ES-82 reduces the TFOV from 2.46-deg down to 2.14-deg.  Not that bad, but...I paid good money for that wide field of view and would prefer not to give it up on that the eyepiece.  I have no issues using a Paracorr with all the other eyepieces.

I suppose a Baader MPCC Mark III Coma Corrector would work since it's 1.0X, but then the Skywatcher 0.9X Newtonian Coma Corrector caught my eyes.  If--IF--it doesn't vignette the 30ES-82, that's a 2.74-deg TFOV with a still-reasonable 6.8mm exit pupil.

Has anyone used the SW 0.9X Coma Corrector with a low-power ultrawide like a 31T5, 30ES-82, 30mm Meade 5000, or a 28mm UWAN/Nirvana for visual use, and would it vignette at f/5?

Clear Skies,
Phil