I see they added a hide/show primary planes button in 2015.
It seems backwards from what would actually be helpful.
I would like to easily be able to turn the primary planes on and off separate from all of my other reference planes.
Right now you have to toggle all planes on, and then you can turn the primary planes on and off, but you can't turn off all the other planes and leave the primary planes on.
This may be what the developers were trying to do, but failed... unless I'm missing something?
It's still the same in 2018 SP2.0. You can turn off the other planes but you have to turn them on or off individually. If you have a lot of other reference planes, that can be a pain. It would be nice if the "View Planes" icon didn't affect the Primary planes.