Interesting thread indeed.
I also worry (or have a dilemma) sometimes.
If I 'm not present, which player the game would sub ?
A 5* AMR in this right position or a higher q (6*) AML or ST playing with yellow triangle ?
My choice would be to use a player with 20-25% higher q in yellow triangle.

I also read somewhere else that the game subbed a 5* DC instead of a 2* GK after an injury.