Most, not all, of us don't watch our trains. Sometimes a train is running when the owner isn't even at the layout.
Usually we are talking, eating, repairing, lubeing, shopping, drooling over someone else's new train, in fact I do all of the above. I think it is part of the overall train show thing.
So perhaps instead of trying to be able to see our train at all times we should concentrate on being able to make a brief glance or survey of the layout to locate a train, and then return to whatever we were doing at that moment.
I like no skyboards on the corners, no or very short skyboards on the yard. I would be willing to try the convex mirrors. I think the HO and N layouts are the same height as ours. 40" rail height is pretty standard but I would also be willing to try shorter legs.