Where I currently do AM Theatre, the Bio Box (aka 'booth') is actually a balcony above where the audience sit - approx. 2 feet at most. The threatre is black box.
The balcony is in blacks to a height of 4 feet, and our current show has the set rotated 90 degrees, so the set goes right to where the balcony ends - we also have no use of the far half of the bio box due to a bunch of crash mats being placed there for an actor to jump over the balcony from the scaf tower - That is a frustrating show to take visuals from.
I am sound op for the show, and cannot see the MOST important visual cue - a radio being switched on - and apparently the blues in the bio box illuminate me too much if I stand to take the cue, so our SM slipps off of his chair, as does the lighting op (due to the daisy chaining of our cans, I am closest in the chain to the base station, then comes the SM with a huge lead between the two of us, then the LX OP), crawls over the crash mats to the far corner, and gives the visual from there, then crawls back quickly as there are 3 lighting and sound cues comming up. We have an ASM back stage, but the set obscewers her view of the stage, so she cannot call it, and she is rarely on cans anyway - our method of calling her is to repeatedly press the flash button. In cases like that, getting the tech director who comes to each performance on cans would be ideal - but we don't have enough cans to go arround.
Then of course due to the lack of separation between us and the audience, all calling over cans is given in a really low whisper - so volume up high. We are even loath to turn pages as the crackel can be heard. Add to that the ammount of hiss due to cabling and of course the fact that no one in the audience seems to listen to our FOH managers pre-show of "Please ensure your mobiles are turned off, not just on silent as the signals from your phone interfear with some of our more sensitive equiptment", each night kills the ears of everyone on cans.
Some times there is no way to make good of a bad situation, all you can do is evaluate your situation as the show progresses, and change as necesarry.