No, at least not in AF 2.1 and earlier. Why not? Formula Data Reference (AF 1.1) existed prior to Enumeration Sets (AF 2.0) and was designed for numeric computations. Short term, support for Enumeration Values as numerics in Formula will be added. The merge of Formula functionality with PE functionality in a future release will add support for handling non numeric types such as string and time.

I noticed that the BadVal function was added to the Formula DR for AF 2 so assumed there was some other rework done to take advantage of the new features.

Formula DR with PE functionality sounds good! Will the Formula DR still be limited to 26 inputs/variables?

No, at least not in AF 2.1 and earlier. Why not? Formula Data Reference (AF 1.1) existed prior to Enumeration Sets (AF 2.0) and was designed for numeric computations. Short term, support for Enumeration Values as numerics in Formula will be added. The merge of Formula functionality with PE functionality in a future release will add support for handling non numeric types such as string and time.