You have to change the toe-in, there is no single arrangement 'great' for either centered or slightly off center.
It’s very doable if you are able to easily alter Toe-In for DBX Crossfield Setup when you have a guest.
excerpt from here
"DBX Cross Dispersion Method (developed for home theater front speakers):
unique shape/angle of dispersion/multiple tweeters: set up once.
speaker your side: closer thus more volume, but, direct dispersion from opposite side speaker increases it’s volume, i.e. a trade-off creating wide imaging. Note: their speakers were designed to provide this without altering their toe-in"
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note: Either way, aimed at center best for single, or DBX aimed opposite side for two listeners sounds terrific from center, it’s just not as wide a soundstage if you leave them in DBX Crossfield and sit in the middle.