I'm off the persuasion that below 18,000 all lights should be on.
There's a reason for that.
SE or ME or Jet.
Doesn't matter.
Used to teach the same.
Taxi light ON for ground movement and add the landing light when taking the runway. If the aircraft is equipped with 2 lights that is.
Difference being angle and sometimes beam width also.
Just makes the light more visible in a larger cone.