I wouldn't sweat the case differences so much. Since the Plus 4C Team, BTT and Bonito all clasify themselves as Plus 2 cases, there are huge differences between the Plus 4 and Bonito alone that you really can't even compare them. Maybe someone with more factory connections can explain it but when comparing the Plus 4 Buggy with the Plus case and the Plus 4C Team or BTT with the the Plus 2 designation, they both use the same internals and the overall design is basically the same. The internal volume, dimensions and flow patterns are basically the same. Maybe because they use a different backplate on the Plus 2 case, they felt the need to change the name? Not sure as all parts, bearing etc. are interchangable so there isn't that much of a difference. I also believe they incorperated the oring on the head button so they enlarged the upper case surface area to be able to seat the oring properly. Maybe some additional case cross cut cooling as well. It has been awhile since I had them side by side so I am trying to remember what I saw a few years ago.

As far as the port counts, I will give you my version and what most consider it. When an engine receives a port count designation, they usually are based on the intake side only and only the ports that are exposed above BDC.

For example, the P5 has 2 vertical intake ports and 3 horizontal ports that are all exposed above BDC making it a 2-1-2 therefore they will consider it a 5 port. The X7 has 3 transfer windows on each side and a booster window in the back of the cylinder all above BDC making it a 3-1-3 so it is designated as a 7 port.

When an engine has say 5 ports above BDC and 2 what the call bypass or satalite ports below BDC, that is where they arrive with the 5+2 designation. The 2 ports that are only exposed during the compression stroke to assist with the transfer and/or booster fill ar not considered intake ports but more of case and port filling aids and therefore do not receive credit for being induction ports but since they assist in the process to some degree, they get added on after the fact as a +2 or 3 or 4 or how ever many holes have been made.

I hope this helped!