Official comment
The firmware versions we support are listed here:
http://support.dronesmadeeasy.com/hc/en-us/articles/205704366
Any firmware versions that are not on that list are not recommended for use. If you have a newer version of firmware it will likely be OK, but there are no guarantees. DJI makes a lot changes and they are not all backwards compatible.
If you have a dev firmware you probably have access to the simulator too so I would recommend trying it on there first.