Isn't this exactly the system Airbus came up with for the A380? Called ACUTE - "Airbus Cockpit Universal Thrust Emulator".
Lifted straight from A380 course notes:
Cockpit Thrust Display (ACUTE)
ACUTE (AIRBUS Cockpit Universal Thrust Emulator) is a percentage
indication of thrust.
The ACUTE function calculates percentage parameters from engine
command and thrust feedback parameters, for transmission to the airframe
and subsequent cockpit display.
The parameters are:
- THR Limit,
- THR Actual,
- THR Command,
- THR REF (Throttle),
- THR Idle,
- THR Max.
THR WML: Thrust windmilling is the THR achieved when engine in
Wind Milling (0%).
THR 100: Thrust 100 is the THR achieved when Throttle at TOGA and
Bleed Off (100%).
THR IDLE: Low-end of grey sector, corresponds to the THR achieved
when the engine is operating at Idle.
THR MAX: High-end of grey sector agrees with the THR achieved when
throttle at TOGA detent.
THR Actual: raw engine thrust corrected by engine drag.
The parameters THR100, THR Limit, THR Actual, THR Command,
THR Throttle, THR Idle, THR MAX, are sent to the airframe CDS
through the AFDX network.
When operating in Unrated N1 mode, the EEC THR parameters output
sent to the airframe CDS are not computed