I know you currently have to name layers with a "+" in Photoshop in order for Character Animator to convert it to a group and give you the "crown" icon checkbox to turn on/off the warp independent option. However, when I'm creating my initial artwork in Photoshop, I'm never sure exactly which layers I'm going to need to set as independent in Character Animator.
So, I end up having to re-open the file in Photoshop continuously to add the "+" to the layer names throughout the rigging process, OR I end up just putting a "+" on every Photoshop layer just so at least I'll have the option of independence when I get into Character Animator (and then un-clicking almost all the crowns to turn independence off the ones I don't need.)
It seems like it would make sense for ALL layers to get imported as groups so they at least have the option to be independent. By default, the group would be deactivated (no crown / independent off) if you didn't name the layer with a "+". The layers with "+" in the name would be the only ones with Independent set as the default, as in the current import process. But they'd all have a box where it's an option for you to turn independence on or off without having to go back to your original artwork and rename the layers.