Magico recommends (like most) finding the best position for bass, then mids, and then toe-in to make the center image natural/stable.
I don't think there is any well-known speaker setup method that solves for toe-in, first.
Not exactly correct, Keith. You are correct that Magico does not solve for toe-in first, but it is not last either. It is integral to the process along the way. I have the "Magico Q3 User's Guide". They suggest starting with the bass which they say is dependent on the distance from the front wall. They then move on to adjusting for the midrange, "placement in relation to side walls". It is in this section that they discuss toe-in.
"We are listening for the image of her voice to be focused. The rule for the toe in is to pick a point approximately 1-2 feet behind the listener's head. Toe the speakers in to intersect at that point. If the sound is too bright, toe the speakers out a little more. If the sound is too dull, toe the speakers in a little more."
The guide goes on to say that the above process should be repeated at a new position, and so forth, to continue to repeat until satisfied. Then in the Summary section, they suggest to return to the bass set up to ensure that the speakers are the proper distance from the front wall. Then, when the process is completed, to "mark the location with tape so that the speakers can be returned there for further listening."
It seems to me that this is a back and forth proposition. It is iterative. Also interesting is that nowhere do they suggest zero toe in. They refer to a precise spot behind the listener's head and then adjusting only "a little more".
I followed this guide and got a sound I lived with and enjoyed for a long time. Then, as I thought more about my reference of live, real sound of instruments, I decided something was not right with my set up. I read a comment on one of David's posts about zero toe-in. I asked him about it. That is when I began the long process of experimentation. Each step along the way, I kept returning to more toe in and it always produced the same type of sound which I was increasingly dissatisfied with, so I held fast on zero toe in and adjusted distance and spacing until I found a satisfying position. This process took much longer than when I followed the Magico method of aiming the speakers at the listener's shoulders and making slight adjustments from there.
My center image is now just as stable, but it sounds more natural than before. In fact all images are very stable. There is actually better localization of images in space than there was before. The presentation is now more convincing. There is nothing wrong with toe in, it just sounds different. A member here who also has Q3s wrote me that he also had great results with zero toe in.
The lesson I learned is that the recommended toe in from Magico for my speakers did not give me the best results in my particular room. Others may have different results.
Have you tried zero toe in with your YG Haileys? With your wide room, it might be worth experimenting.
