Fixed wing world it seems to be slightly different.
You don't need to have a MCC in fact quite a few use it to get an exemption.
The aircraft doesn't require to be MPA from as soon as its being used unless it has a mod which means that the SPA stuff isn't reachable by a single crew eg the second altimeter can't be adjusted.
there are three inspections that need to be passed.
1. The aircraft that its equipped to be MPA.
2. OPs manuals and SOP's are multicrew.
3. Training is to be multi crew along with line checks, OPC/LPC etc.
A lot of it is in the hands of your ops inspector some don't like crew being qualified SPA and MPA on the same type. Some will let you. Some will say you need a MCC as part of initial training others don't require it.
There are shall we say some experts out there in getting the manuals together and all the boxes ticked. And it can be a bit involved.
Once you have it both pilots can log the time and the co-pilot can log PICUS as well (make sure you define that in your manuals).
I don't think its possible to do unless your on an AOC. Or if it is I have never heard of it.
Oh and you can be PIC without an ATPL.