BX23S grapple controls

I picked up my BS23S from the dealer last week. I had them install a grapple when I purchased it. I needed to do some bucket work, so I disconnected the grapple and noticed that both connectors on the tractor side were male and both were female on the grapple. If I understand correctly that means I can set the open on the grapple to either the loader dump or curl. Is there a standard where open should be set on either dump or curl? I don't want to learn one way and have it be totally different if I get the opportunity to use another tractor. The dealer had it set so the dump function closed the grapple when using the switch.

One other thing. When you disconnect the hoses from the Kubota third function, there are no dust covers on the tractor side. Just on the hose side to the grapple. My dealer said that the third function connectors on the tractor did not come with dust covers. That seems strange that every other connection has dust covers for if the hose is disconnected. He also said I was the first one to ever ask about it. Just wondering if that sounds right.

I may have used the wrong term. It may be a diverter. You have an on off switch. You turn it on, then press a button on the stick and use the curl or dump function to open and close the grapple.

Edit: My paperwork says 3rd function valve, but I think it is just a diverter since you have to hold the button to open or close the grapple and let go to tilt it up and down.