Is there a way to get motion 5 effects to play back at a set speed in FCPX, regardless of clip length?

When Motion 5 effects and generators are applied in FCPX, they play back at a different speed depending on the duration of a clip. This can be very frustrating, as multiple effect parameters must be published and adjusted inside FCPX every time a clip is trimmed.

Examples:

I'm using a generator to create sparks.

I'm using the 'oscillate' parameter behavior to bounce a movie clip up and down inside FCPX.

I can't see why anyone would want the duration of a clip to change the appearance of an effect or generator. Is this flawed by design or am I missing something? Anybody got a work-around?

Thanks!