Replaced footage in mogrt - keyframed motion not rendering in Premiere

I created a mogrt in After Effects, which needs to be used by an editor in Premiere. The media replacement works fine when used as a comp with essential properties in AE, but doesn't work properly when imported into Premiere.

Keyframed motion I apply to the replaced footage (such as increasing scale over time) is not rendering properly in the main sequence. The animated motion either begins and stops, or jumps around. The mogrt file uses protected regions in order to preserve the durations of the start and end animation, while allowing the editor to change the total duration.

I'm unable to attach a mogrt file type to this message, so here's a download link. Am I doing something wrong or is this a bug?

Thanks!