Do you really want to remove all guest artist from artist tag? Then you won't be able to find those tracks via their artist tag.
Yes.
To explain, I plan to use this when adding new tracks to my library, not to update existing files. I'd like help creating a Preset in the Advanced search and replace plugin that will instantly do what I've outlined in the OP, so I can quickly update new tracks when I add them.
I'm aware MusicBee can do so much more with artists/featured artists/split artists etc, and ultimately, I do have plans to tidy up all of my tracks with a featured artist and make used of what MusicBee can do, but I've only recently made the switch from iTunes and I have a whole ton of tracks set in this way at the moment, so for now am continuing with it.
Thanks for your help, but it hasn't worked. I'm not sure if there's something wrong with the code you've given or if I've not followed your instructions properly? Here's what I did:
1) Went to Edit Preferences -> Tags (1) -> Define New Tags...
2) Created a virtual tag with label
Featured Artist(s) and formula
<Title>$If(<Artist>=<Artists>,," [ft. "$If($Split(<Artists>,;,2)=$RSplit(<Artists>,;,1),$RSplit(<Artists>,;,1),$Replace($RxReplace(<Artists>,"^[^;]+;\s*(.*);\s*([^;]+)$","$1 & $2"),;,","))"]")3) Put an album in my inbox that had featured artists in the Artist tag in the way I said in OP
4) Right-clicked one of those tracks, went to Additional Tagging Tools -> Copy tag...
5) Copied the new virtual tag to title and clicked Preview. But no changes were made: