WAP-5 can't handle gradients, AFAIK, which was one of the reasons why they were restricted to only BRC & GZB for a long time.
But then 22415/6 was often spotted with WAP-5 couple of times, but don't know whether it had bankers at that time or not, possibly because 22415/6 was lighter than 20805/6 in terms of CC & hence load.
There would be banker attachment & detachments for 20805/6, I guess.