Using Mandatory in and out markers without effecting the timing?

I am creating two basic drop zones. They both animate in and then out so I used the markers Mandatory In and Mandatory Out so that on the FCPX timeline, no matter what duration a clip is, and if I trim the generator to fit the clips' time length, it will still animate in and then out.

But how do you allow the timing to not be effected? Because if you trim the generator the footage will go fast and if you stretch it out the footage is slowed.

Thanks a ton for any help!

Opps...sorry. I failed to mention I am creating a template in Motion to go out to FCPX.