And of course I want to be able to keep my music all tagged properly with semi-colons as I have been where it's appropriate. Advice or thoughts?
I'm curious as to why you think that having the semi colon separated value in the album artist tag means it's tagged properly. It's not. Album Artist is a specific, definable thing: It's the way the album is credited on the jacket/sleeve/cover etc. This album is credited to "Freddie Gibbs & Madlib" according to Musicbrainz and last.fm. For it to be properly tagged, that would have to be the Album Artist tag. Although you can use semicolon-separated values in the Album Artist field as kind of a navigational kludge in MusicBee, it is not standard for this to be a split field, and I'm not surprised that it breaks trying to match up with other sets of values. It is a singular thing across an album.
Scrobbles usually include Title, Artist (Display Artist in this case), Album, Album Artist, Duration and Time Played. I don't know exactly how Musicbee does it, but those are the usually expected fields.
To be tagged properly, you'd want Display Artist to match the way the track is credited, then in the artist splitter list the individual artists for browsing purposes, then the correct album artist according to the source you're trying to match to (last.fm in this case). Then, in your view, you can set your thumbnail browser to "Artist: Artists" to be able to navigate to the individual artists' listings as you're trying to do now with Album Artist.
EDIT TO ADD: By the way, I'm not trying to say that you shouldn't do it your way, just that what you're trying to do with it isn't going to work your way. It's all what you find to be most important - proper matching or tagging the way you want to.
For example, I've got all kind of funky values in my Album field ([2018 Deluxe Edition], [2001 Remastered], etc) and I've come to accept that these will never exactly match what's in last.fm's database, but I can't change them now or it will screw up my synched play counts.