Mogrt (made in AE) with in/out sound fx (extendable in Premiere Pro)

In AE I want to create a mogrt (with a textbox) that have also an in and out sound fx.
I use responsive intro and outro for this. I make sure in “unprotected area” not to have keyframes or audio. 
The problem is  when I import the mogrt in PP , it can’t be stretched

Thanks for any help

Chris