(Expanded) UPDATE (as promised above):
First Night
Outdoor, small town street dance, stage was your typical semi flatbed trailer which sits a good 4 feet off the ground if not higher. Got there, asked the BL if he was good with experimenting with center cluster subs, he said sure no problem. We laid all 4 subs end to end in the center and they just fit under the trailer so that worked out great. Then the tops got set on the "stage" 2 per side.
We soundcheck, everything sounds real good but the BL hasn't heard it yet. That happens when he goes out about 2 songs into the show and when he comes back onstage he points down to the subs and looks at me with a big grin and a thumbs up.
Second and Third Nights
Inside, a large 2-story bar (350 capacity I'm guessing) with a "log cabin" theme, i.e. tall ceiling, lots of wood and a stage about 2 1/2 feet off the floor. This time BL suggests we center cluster the subs again only this time we lay two of them end to end on the floor (right in front of the stage), and then one each laying on their sides on each side of the stage, with the tops stacked vertically on top of them.
This setup looked impressive and sounded even better... without question the best I've ever heard our P.A. sound. On top of which, the two subs on the floor made a nice "apron" that the hotties really seemed to enjoy dancing on (wonder why?...), and with the other two subs flanking the stage we got a whole lot of "thump" as a band that complemented our IEMs to give us truly great stage sound.
I apologize for not having actual photos, but I wasn't in position to take them. But if anyone has follow-up questions please feel free to post here or PM me directly.
Suffice to say we will be clustering the subs whenever possible going forward.