I've had no problems with the latest firmware, which adds the RID to the drone as required. I had to update both the aircraft and install the latest version of GO4 in the Smart Controller right from the DJI website. After updating everything and...
They'll also work on the original Smart Controller (RM500), which has an HDMI output port. That's a good price, I remember a few years ago when they were substantially more that.
Depending on where you fly, and as long as you fly it as intended, you won't have any problems whatsoever. Also, the "trust" certificate thing is very simple and only takes a little while to complete. It's basically all common sense answers.