A lot of CC3+ characters, when exported to FBX are not stable on the ground. They are either above or below ground in an A Bind Pose.
Many of them slide forward by Y. This cause some problems while modeling and importing modeled cloth or accessories back to CC. Specially when exported with calibration clip.

All, except CC3_Jody. This character has a zero slide for instance when exported along with calibration clip or other poses.

You can actually verify characters behavior in advance before the export:

1. Switch camera to side orthogonal view
2. Start Adjust Bones tool. CC3+ characters would take an A Bind pose and most would raise by Z (some would be lowered by Z) and only CC3_Jody stays firmly on the ground (I have not tested all of them though). See the screenshot.
Aside from that most would have a Y slide between an A Bind pose and Calibration clip. Again only CC3_Jody in my tests is perfectly stable by Z and Y.

Please make all CC3+ characters like Jody. Aside from general problems, this export discrepancy creates a bad impression.
Please make them all have uniform and professional look on export.

Side note: Just wish to reiterate from the other ticket, that creating cloth in A Bind pose and returning character with FBXkey back to CC in T Pose is not a good idea. Make an A Bind pose available in CC.