I suspected as much re T/S/S.com etc.
These seem to be the others with 1.8mm:
P1/X1 Extreme through Gen 3 with Intel 10th.
P15s, P15, P17 through Gen 2 with Intel 11th.
P14s(i) through Gen 2 with Intel 11th.
P14s(a) through Gen 2 with AMD 5th.
Probably the parallel T series to some of the above have 1.8mm but IIRC in some cases the equivalent T didn't offer a UHD display option so that's why focusing on P, although maybe this is just now changing, with poor RGB becoming less common on T even for 1920x1200 res and with decent 2560x1600 perhaps becoming the mainstream baseline.
Unless I missed something it looks like the P15v Gen 3 (a and i) and the T15p Gen 3 (just i) are the only subseries with 1.8mm that got to Intel 12th or AMD 6th.
I really just want the electronics and display of a P15v or P1 or Legion inside one of my old T520 units --- heck they are big and heavy enough to contain a full bore P15 --- but coming back to earth I wonder if a decade from now I'll just have a single laptop for travel like my X1 Carbon (by then the Intel 23rd gen model), a tablet, a phone, and a mini desktop to sit on my desk with any keyboard and trackball or mouse I want. Sigh.
Thanks much for the advice and keep up the excellent work, it's invaluable stuff.