Thank you to all who have been helping me with this.
Man, what a challenge! Am I the only one who works all day with the device sitting on my desk in front of me and wants to tap and swipe to use it, without having to lift it up off the desk or maneuver to hit the Power button to wake it -- which is required literally many dozens of times a day?
I had decided to resign myself to using a Bluetooth connection to keep the phone unlocked, which is certainly not as secure as I'd like but I have to consider usability at well. At least that would enhance productivity compared to first waking the phone and then unlocking the phone with taps and gestures dozens of times a day. I hoped with perpetual Bluetooth "unlock," a single-tap on a black screen would get me "in."
In fact, one thing I found that makes it less of a concern to be keeping the phone unlocked when on a Bluetooth connection is
the Lockdown option, though it does require remembering to manually activate it when, say, leaving the phone (and Bluetooth device) in the locker at the gym or taking off the waist pack for a swim.
There's just one problem, though! While using a Bluetooth connection can keep the phone "unlocked," it seems it will not keep the phone "awake!" And for that, one
still needs to hit the power button on the side of the phone!
The only choice left is keeping the screen on all day with the device sitting on a charger all day, and burning out the battery life really quick at about $130 a shot to replace the battery -- and probably ending up with screen burn-in, requiring a new screen periodically at about $230?
Either someone at Samsung or Google really missed the mark with this, or Samsung is trying to push people to buy an S10 or Note10 for the on-display fingerprint sensor.
Maybe this will come to the attention of a development team and be "fixed" in an update, though that seems highly unlikely at this stage.
Maybe it will be there if and when Android 10 is released for the S9?