Castle BEC Update

I got couple of them just recently. I thought they were old stock or something as I didn't hear anything about an upgrade to them.

Anyway what is the point of the cap on them. To me it looks like it is on the input side. I could understand if it was on the output side to help level out the voltage but have no idea why have one on the input where there really shouldn't be a dip in voltage bellow 6V. Maybe I am missing something so if someone could explain it I would very much appreciate it.

Also I can't see a difference in operation with the cap version compared to one with out it. Both seem to hold voltage just as well with similar HV servos.