Picked up a Tab S3 and did a quick test this morning. It works exactly as expected and sequence of powering up devices does not matter (unlike Tab S2).
App/Version
Android 7.0 (Nougat)
DJI Go 3.1.4
P3A 1.10.90
RC 1.80
Also note, it fits into the device holder of the RC without an extender...