Good to hear more of your hands-on experience of adding shotguns to an existing array. As I've mentioned before, I suspect the other mics in the array help to hide the off-axis issues of the shotguns, particularly at the levels at which you are using them. Also, it's somehow comforting that your setups make my arrays seem almost tame in comparison.
I should try your single PAS spot shotgun technique to get that little extra bit of vocal clarity in the mix, always a fundamental challenge. For others following, that's a single shotgun pointed at whichever PA stack is closer, louder, and clearer, with its output panned to
[edit]center in the mix, or to whatever position helps perceptually center the vocal/PA content. Yes, that means that microphone is intentionally arranged asymmetrically with regards to all other microphones in the array, yet it's output ends up being used symmetrically in the mix.
[edit- In actual use, was the actual angle between the two shotguns as small as it looks in the photo? It appears pretty small, maybe ~15 degrees or so. Just trying to parse if the inclusion of only one of the two might have produced a similar result. Maybe you played with that in the mix?]