I have no experience or familiarity with Attribute Assistant, however if you want it embedded within a IIF statement, MS access if the closest I have that contains the IIF function....
Putting this into a single line IIF format is ugly .... (ReformatDateString is a value field)
DatePart("yyyy",CDate([inspdate])) & "/" & IIf(DatePart("m",CDate([inspdate]))<10,"0" & DatePart("m",CDate([inspdate])) & "/",DatePart("m",CDate([inspdate])) & "/") & IIf(DatePart("d",CDate([inspdate]))<10,"0" & DatePart("d",CDate([inspdate])),DatePart("d",CDate([inspdate])))