Inconsistent motion behavior
Hello, thanks for a great library.
I'm having an issue when using the CustomSlidableAction to place my own widgets as Slidable content. I'm using the exact same code for both start and end panes, but for some reason the start pane motion behaves differently compared to the end pane. I will add some images to explain:

The white area is the Slidable child content, and the blue/pink areas are the start/end panes. Here you can see the startPane behaves like a StretchMotion with the icon being revealed from under Slidable child.

On the endPane, you can see that it behaves as a ScrollMotion pane, with the icon being pulled in from "out of the screen".
In both cases, the motion is specified as ScrollMotion (this is what I'm aiming for), and I would mention that no matter what motion I specify, the behavior on both panes does not change.
For some more context, I have only one CustomSlidableAction child in both panes, and I'm implementing the component using DismissiblePane to have a single action on each pane when sliding the whole way ("dismissing").
Please let me know if there's any other info I could provide. Thanks!