No worries @ChrisStephens, and perhaps still an alternative...
I wonder if the IFIN function on the same article be a better fit:
IFIN(value, value1, value2,..., trueExpression, falseExpression)
such as
IFIN({DE:Variable}, "A", "B", "C", CONCAT("calculation 1"), IFIN({DE:Variable}, "D", "E", "...