Interesting thought, and very doable. I think the Q-factor is on the large side for people of average size and down already. I use 200mm IRD cranks, which are also a bit wider than an S brand crank, which in turn are pretty wide compared to bikes of 30 years ago.

Switching back and forth to my MTB, I do like the wide cranks, especially out of the saddle. But when switching back, narrow feels more spinnable, and more aerodynamic. Other than that, I haven’t experimented enough to know that a certain width would be better. Compared to length, it seems less important.

I would not mind reducing dish in my rear wheel by going a little wider. Maybe I will next time.