XT32 +the App is a great way to play.
The App gives you the "Before" image of your FR. Frankly, this is one of the more valuable things about the app, IMO.
My understanding is that any of those Mics can have roll-off issues. Perhaps a crap shoot as to what you get. *shrugs
Re: BMR tipped over for Center usage, with the Raal rotated a corresponding 90º... I have no complaints. Nor do I recall seeing any weirdness in my FR. I still plan on getting it turned upright, soon. That is my ideal, anyway, but not do to anything I've seen in measurements; just preference.
Cheers!