okay, so as-is, the script you wrote removes the spaces between the artist names and join phrases for %main_artists% and %guest_artists%*. I don’t foresee me using these values for my script as I’ll be using the multi-value tags, but for anyone else looking to use these tags, that could be an issue… apart from that, it’s perfect~ I can prolly work it towards my use case from here~ 
(and I’ll of course post the resulting script over on the other thread linked in the OP)
*%main_artists% for the first example became Antoine Dodson&The Gregory Brothers and %guest_artists% for the second example is lil aquafinaprod.aaron kates
edit: I also had to remove the parentheses in the $noop() at the beginning… lol
edit 2: posted here~