I must have made a mistake with my syntax on foo_albumlist, because you can have duplicate track entries in the separate nodes providing they have the necessary multi-value tag, eg %<artist>% or in my case %<CHART_BILLBOARDTOP100>%.
It just wont translate it into duplicate entries in the playlist.
Nope, can't do it with foo_albumlist
"Any string manipulation function that removes a part of a string or inserts a substring by position is generally unsafe. This includes $left(), $right(), $cut(), $pad(), etc."