It has been sitting on the "Downloading, Do not turn off target" fugly blue screen for the past ten minutes.
Did some more research based on getting that screen. One site lead to a link which lead to another which... you know how it goes.
There's the Download screen (duh) for flashing or rooting. It will stay there until you start the rooting/flashing process or you press/hold the vol down, bixby, and power button until it goes black, then release.
Then there's safe mode. Hold power button down beyond first screen, release at Samsung screen. Immediately press and hold the vol Down button until it finishes loading. I have not tried this.
Then there's recovery mode. To do recovery mode, press the vol UP, bixby, and power. When the first screen shows, release power key. It will then go into recovery mode. Releasing all three did not work for me. I had to just release the power key.
Got all that here:
https://thedroidguy.com/2017/08/run...tition-perform-master-reset-tutorials-1075547