I think I know the answer... just looking for validation.
There is an ambidextrous pitcher and a switch hitter. Pitcher is throwing lefty. Batter gets in the box as righty. Pitcher steps off and switches hands. Batter then switches sides... it goes back and forth, each switching when the other does. I know NFHS rule, 6.1 "the umpire shall require the pitcher to face the batter as either righty or lefty, but not both." There is also no rule that a batter can not switch sides during an at bat. But if the pitcher hasn't thrown a pitch yet, then he hasn't faced the batter and can switch up until the first pitch. I would make the pitcher declare then not permit the switch. Is that correct?