It is still a very cumbersome work flow, I'm sorry. I already blogged about it over 4 years ago, and although some features of Effects have been improved, not this one.
Editing Motion Paths and Reusing Customized Effects - Captivate blog
This is the work flow:
- Create the wanted effect as a time-based effect, where you can edit the motion path.
- Save that effect as a custom effect, location is not important, you'll just have to remember it.
- Delete the effect
- Apply the custom effect to the object again, you'll have to browse to the location where it is stored.
- Delete the effect again.
- Now that effect will be shown in the 'Custom' category in the dropdown list, when you choose Apply Effect in the AA dialog box.
Even in CP9, where the Effects have been integrated in the Timeline panel, and live preview is possible, where you can edit duration and start time in AA, this work flow for motion paths is still the same as when Effects first appeared. At least, it is possible.
Oops, I just see that it is in a responsive project. I didn't double check what happens in the lower breakpoint views.