I don't know about this B2/B3 "confusion", as this image (EIXOS) is too old, MegaMOZG could be changed assignments later.
To avoid more confusion, what picture you guys suggest for replace this in the start of this topic?
I have been using the WIKI Assignments , on the Compatible Controller Page here : ***edit ...the forum won't allow a direct link to the Compatible controller page ( page 2) for some reason ?
but the link is : https://github.com/MMjoy/mmjoy_en/wiki/Controllers-(compatible-base-boards)
The 1st one is the Pro Micro ( by Sparkfun but now many Clones available too) , which I will use for my next Conversions as the Leonardo was a very tight fit in the FLCS, though I may use the Micro ( not Pro) instead since I now have some of both.