If you keep adding things to preferences, there will be hundreds of different preferences available, and we will have feature creep.
To be honest, a casual game means exactly that - casual. I'm not going to be playing my best in a casual game, nor am I going to analyse it or go over it. I will be playing casually, and assume my partner to be doing so. I only play casual to warm up, or to practice an opening and then resign. For me, in either occasion, I could not care less if my opponent is using an engine.
Also, if it's such an easy fix, feel free to produce it yourself - the github is public, after all.
To be honest, a casual game means exactly that - casual. I'm not going to be playing my best in a casual game, nor am I going to analyse it or go over it. I will be playing casually, and assume my partner to be doing so. I only play casual to warm up, or to practice an opening and then resign. For me, in either occasion, I could not care less if my opponent is using an engine.
Also, if it's such an easy fix, feel free to produce it yourself - the github is public, after all.