Hello John,
a couple today's tests with TBM9:
I converted the new offset in ft/m from ft/s and changed sign in order to be comparable with the original one
LIQL
14.25.58 - [Leg] Landing detected. Landing rate: -162 fpm (Last VS: -142 - GForce: 1.21 - Normal: -192.0) RWY 10
VNLK
14.39.25 - [Leg] Landing detected. Landing rate: 945 fpm (Last VS: 1030 - GForce: 1.50 - Normal: -432.3) RWY 06
14.44.14 - [Leg] Landing detected. Landing rate: 478 fpm (Last VS: 273 - GForce: 1.00 - Normal: -244.7) RWY 06
LFLJ
15.03.35 - [Leg] Landing detected. Landing rate: 1709 fpm (Last VS: 1754 - GForce: 1.38 - Normal: -407.0) RWY 22
15.11.15 - [Leg] Landing detected. Landing rate: 1278 fpm (Last VS: 1200 - GForce: 1.34 - Normal: -262.9) RWY 22
LIDP
15.18.21 - [Leg] Landing detected. Landing rate: -54 fpm (Last VS: -96 - GForce: 1,05 - Normal: -88,9) RWY 02
15.23.13 - [Leg] Landing detected. Landing rate: -165 fpm (Last VS: -149 - GForce: 1,22 - Normal: -231,3) RWY 20
The values seems reliable.
I will continue test in bigger airports with liners and I'll let you know