(I tried posting here yesterday. After a few edits, the forum deleted my post. So per Bob’s suggestion I’m trying again.)
I record with higher-order ambisonic (HOA) microphones that allow for virtual stereo pairs and more.
A single HOA mic allows for any coincident mic array that you can imagine. The polar patterns and pointing directions are selected in post, and from a single recording you can do as many virtual coincident arrays as you like, including Blumlein, XY, LCR, binaural (both headtracked and fixed-head, with computed ITDs), and many others.
With two spaced HOA mics, I do ORTF and bilateral ambisonics (for binaural recordings with a true ITD).
All the parameters of the virtual mics are decided in post-production, except for the spacing in spaced arrays.
The HOA mics retain their full frequency response specs, even when decoded to directional polar patterns.
Here’s a link to a short clip of the Montreal Symphony Orchestra playing Dvorak’s New World Symphony, recorded with a single HOA mic decoded to Blumlein: