Thrust lever angle??? What do I care what the angle is?
It's a major input to the logic of many systems. Aircraft have moved on a long way and I get the feeling your a little behind the technology curve mate.
Even the engine FADEC uses TLA as a thrust request. By that I mean that the quadrant is divided with certain flat spots that request a specific thrust rating rather than an N1 figure.
So 72-80 degrees will command TO thrust but the actual N1 will depend on how TO thrust was defined on the take off data set page. 68-72 degrees will give Climb thrust. The actual N1 will depend on Air Data at the time. The idle de-tent ( around 24 degrees) will request idle thrust. That could be ground idle, flight idle, approach idle or final approach idle. All different but all commanded by the same TLA.
Speed brake will retract if the thrust levers are above 70 degrees
Ground spoiler will deploy if among other things the TLA is below a certain angle, and retract if the TLA angle goes above a certain threshold.
Other systems use TLA in the TO range to activate appropriate logic for the take off phase of flight for example anti-ice and ECS (air-conditioning and pressurisation).
You can neither start or stop an engine if the TLA is not in the idle range.
We know you are anti automation but take it from me. The world has moved on and the automation you dislike actually saves lives every day.