OK, finally seem to have it squared
The small black box under the upper, center, light console on the headliner, nearest the rear-most compartment, IS for the tire pressure warnings. Since my tires are OK with correct pressure and the warning was appearing randomly, unhooking the black box disabled the tire pressure monitoring 100%. So no warnings, nothing. It's as if the feature wasn't added to the car. The center display won't show ANYTHING tire related.
To get the SOS and Cell phone warnings to vanish, unhooking the box behind the passenger taillight
https://www.lincolnvscadillac.com/forum/attachments/vmod-jpg.828569496/ as seen in FlaOkie's no.3 further up (thank you again for putting that up),
completely removes the cellphone and SOS warnings. It has 2 plugs and a very tiny antennae terminal connected. I just unhooked all 3. It's behind the flimsy carpet/plastic trunk panel immediately behind the passenger tail light on the rear inner 1/4 panel corner of the trunk. Takes about 10 seconds to pull the cover aside and unhook (thought it'd need a bunch of stuff pulled down so kept putting it off). Didn't need to mess with anything under the rear deck tray.
And to be clear, you start the car, the message read out on the dash cluster completely bypasses the SOS, cell phone, tire, etc. check/warnings when starting up now. Putting the car into gear, it remains on whatever was last selected i.e. avg. mpg, trip, etc.. NO MORE superfluous warnings of 20 year old technology no longer used/needed.