>>3885376BRAW is available on the S1H, you're absolutely correct.
But as far as I can tell, it's only the S1H. The S1 and S5 are only ProRes RAW. The GH5 and the BGH1 are only ProRes RAW.
Even within MFT, Olympus' E-M1 Mk III and the E-M1X are only compatible with ProRes RAW.
BRAW support is only found on the Canon EOS C300, Panasonic S1H, EVA1, Nikon Z7, Z7 II and Z6 and the Sigma fp and fp L.
So why can't Panasonic bring BRAW to more cameras, like the GH models?