No worries, its a good conversation.
"Taping a PA from front of house in an ORTF style or similar config, with mics spaced and angled reasonably and consistently (or the same) in all situations, sub cards or omnis will give you more reverberant response than supercards will."
That's right. In that case, if constrained to that recording position and that microphone spacing and angle, by changing the microphones to a more directional response such as cardioid or supercardioid, you will increase the direct/reverberant ratio in the resulting recording and get more direct sound and less ambient room sound.. And you will also change the stereo imaging at the same time.
Do you really want to change both the direct/reveb ratio and imaging in that way? Simultaneously? Probably not. It's far more likely that the choice is sort of made for you by your gear. Perhaps you only have one mounting bar that provides an ORTF setup of 110 degrees at 17cm, and you can change to mics with a different polar pattern but not change the angle and spacing of them. That kind of thing is common around TS.
What would be more appropriate would be to also change the angle between microphones, or spacing between them, or both, when changing to a different polar pattern microphone. That would allow you to maintain similar imaging, or adjust it independently. That was my motivation for working up the "Improved PAS table" I posted here a number of years ago to help tapers who didn't care for figuring out all this theory stuff and just wanted to make a decent recording in a crappy situation. It makes managing that spacing/angle/pattern relationship simple by reducing the variables to simply pointing supercardioids at the PA speakers and then determining what the appropriate spacing between microphone should be base on the resulting angle between them.
"It's definitely possible to get a wide imagine with a pair of narrow polar microphones, but wouldn't you start to lose your center at a point?"
Not necessarily, and not any more than using some other polar pattern instead. It all depends on the other variables of the setup. Could also get a weak center from an over-wide omni recording, which is probably more common.
.."cards or sub cards at a 90 degree angle from each other will have a wider perceived image than super cards at 90 degrees. There's not much of a point in recording a PA with supers or hypers facing 180 degrees away from each other"
Actually the opposite. In terms of stereo imaging, with identical spacing between microphones, a pair of supercards at 90 degrees, will produce a wider playback image than a pair of cardioids or subcardioids. If the recording position in the room is reasonably close enough, they will also pickup less room reverberance, which could possibly be described as sounding "narrower" but that's something different and mixing up two different aspects.
Some may find this hard to believe, but I record using supers and hypers facing 180 degrees from each other all the time. Granted I also have another microphone in the center between them facing forward (and usually a fourth facing backwards), and that arrangement is which is what allows me to adjust the EQ and level of sound from each of those directions somewhat independently from each other. They are still highly interdependent, but the degree of freedom it gives me is invaluable and a big part of what I was describing previously.
And here's something about that which I found very interesting, which is totally relevant to this thread-
Even though I would never record with just a single pair of super/hypercards facing 180 degrees apart, and certainly not with the 2' to 3' spacing between them that I'm using when I also have the other mics combined with them in the same array, I found that when using excellent quality microphones with very well behaved polar responses in a good ambient position where the direct/reverberant ratio is correct for a pair of spaced omnis (outside in an amphitheater, FOB), when muting all the other channels and just listening to the pair of sideways facing super/hypers alone over a stereo pair of speakers it sounded very good. Amazingly good. I fully expected a huge hole in the middle. I fully expected mostly ambience and muddy direct sound. But instead it sounded totally acceptable. I attribute that to two, maybe three things: The environment (the outdoor amphitheater and the direct/reverberant ratio at my recording position in it); the very well behaved polar response of the excellent microphones I was using, even far off-axis; and perhaps the nature of recording a large PA (I was centered, and as is typical much of the mix was mono, and that probably allowed the over-wide spacing to work without too much 'hole in the middle' similarly to how very wide spaced omnis can work in the same situation without too much 'hole', even when that would not work in other situations. Recording a mono-ish mix produced over a wide spaced pair of PA speakers, from the distances we are commonly doing it, is not a normal recording situation in any acoustic situation other than live concert tapers. Yeah I know that doing that is typical around here, but it's a totally freak oddity in the recording world really).