Differential Amplifier with Global Negative Feedback
The original question asked about "cancelling output distortion". This answer shows the diffpair ADDS its own distortion, uncancelable distortion.

with 200 milliwatt power dissipation in your diffpair, you will experience lots
of thermal distortion. Put in a clean square wave (into the actual circuit) and examine the overshoots (or undershoots) on pulse leading edges.

You can model this in SPICE, using voltage-controlled-voltage-sources to modulate a DC voltage in series with base or with emitter, that source changing
-2 milliVolts per degree Centigrade of collector heating.

Now if you just had a good thermal model of those transistors.

Assume each is 100 micron cube.
1u cube is 11.4 nanoseconds
10u cube is 1140 nanoseconds
100u cube is 114000 nanoseconds (114 microSeconds)

Given 4+ milliamp through R1, and 50 volts Vce across each of Q1 and Q2, there is at least 200milliWatts total in those 2 devices.

You care about the transient thermal resistance.