Cool library, I've enjoyed using this!
I've noticed one thing when using formula validation. I passed in a validation routine like so:
Call field.AddFormula({@Length(@ThisValue) != 11}, "Field should be 11 characters long")<br/>
… and this will always fail (at least, where @ThisValue equates to a text field), because the Evaluate routine in RunFormulaValidation() adds double quotes to the string (thus making it 13 chars instead of 11)