3:2 and 4:3 equivalent how?

Whatever. I have personally used paid versions of DxO and Silkypix, and I know that the access to additional (horizontally oriented) photo-sites continues to be a feature. Ask Guy Parsons ...

I tend to go with 1st-hand experience that I have myself verified - as opposed to things that I may find on the internet that I do not directly know about, and which (as a result) may be subject to misinterpretation at various levels outside of my ability to check and to verify facts.

Tonight I opened the E-M5 ORF RAW (that I found "Image Dimensions" of 4640x3472 in the image-file meta-data) in RAW Therapee 4.0.9.184, and (with no rectlinear distortion or other geometric corrections in effect), and the maximum possible pixel dimensions were 4632x3464.

Put that in your portfolio of virtual knowledge.