^ Can it do the same when recording directly to b-format? If so you might skip writing or storing a-format.
For those unfamiliar:
a-format = direct microphone capsule output (front left up, front right down, rear left down, rear right up).
b-format = universal ambisonic format (W,X,Y,Z) (omni, front/back, left/right, up/down) t, can played back ambisonically, manipulated in post, converted to stereo, binaural, 5ch, etc..
The potential issue with storing a-format is that there can be different forms of it. It might be "microphone specific a-format" rather than "universal a-format" which can be converted back and forth to B-format mathematically. The manual or H3-V3 discussion groups may shed more light on all this.
The Tetramic for instance includes calibration files specific to the response of each capsule, used in conversion from a-format in addition to the more generic conversion info such as the spacing between capsules, applied when processing the raw file data. With the Tetra, if you only have the raw a-format files stored, you also need the calibration files and conversion software to convert to a usable format. I won't bother you with the details, but I'm lazy and still I have most of my Tetramic recordings made years ago stored as raw a-format files and need to convert them to B-format for more accessible long term storage. In the H3-VR that processing is likely done in the recorder prior to storing the a-format file and invisible to the user, which would make it's a-format more "universal" than Tetramic a-format files.