You are correct, FW version 3.16. DJI has a thread explaining the updates in this firmware about 10 threads down from this one . I would try to stick with the Sbus if possible, sure makes a neater install and saves a lot of time fiddling with a bunch of leads. You can pick up Sbus (typeI) rx's used fairly cheap if you don't want to mess with updating to 3.16.A;so i believe the latest firmware update addressed S-BUS2 problems but I have not tested it yet, I plan on using my 7008SB Rx on my new Disco Pro build but still waiting for it to arrive........
Pete