Custom Transition “Slices”

I’m trying to create my own custom transition that “slices” the video and then each slice slides away revealing the next clip.

I would want the option to choose how my video is sliced (vertical, horizontal, and each diagonal).

My idea was to create this Transition from a Motion template and use multiple Transition A placeholder/Transition B placeholders masked and animated to reflect each choice and then create some sort of rig or published parameters to select which type of transition I wanted when I apply it in FCPX.

Of course, Motion does not allow multiple Transition A/B placeholders in one Transition Project. How would I create this transition without having to make a separate transition for each one?

I did try to create just one version of the transition, but it still proved impossible because I’m not able to create a duplicate (cloning doesn’t work either) of the Transition A/B placeholders.

Check out my attachment for a Motion project with the animation I am thinking about.

Here's a followup...

If I can't make a Transition, could I make a Generator with a Rig that allows me to turn on or off specific groups? The idea being, I could use the drop zone project I attached, save it as a generator, and use a Rig that allows me to turn on just the group that has the animation I want.

OK, so I did publish as a Generator. I had to publish all instances of the Drop Zones for it to work properly, and I published the Opacity sliders for all the groups to complete it. I find this a little clumsy, I wish there were a simpler way to do it, but it gives me the controls and look that I want. Granted, creating a transition by way of a Generator is going to make my timeline a bit messer because I have to have my B clip as a connected clip under the Generator, but hey, it works!

This is an example of what I came up with. Bare in mind I left all the different types of animations visible, because I thought it kind of looked interesting with the drop shadow, but I can choose just one or multiple. That would be something I imagine would not be an option if it was an actual Transition.

The solution is easy, and you're actually 90% there.

Create a Pop-Up menu Rig. You'll set each menu option to turn on and off each layer's Opacity as needed. Name each menu item in that rig. Done.

Awesome! Thank you.