since mini-BOS is a different bottle for NHC, 187mL bottles are more than sufficient IMO. Two people, and 7oz (if filled to the rim) is plenty. Three judges? Still enough.
Want a data point? I entered my ice cider in GLINTCAP in 187mL bottles. I brought them 4 bottles, they took 3. They use 3 judges for everything.
It was gold, runner-up for Best in Class, and there was still 1.5 bottles left to enjoy at the gathering afterwards.
Mead is expensive and dear, and 5x 12oz bottles and $14+ 2x shipping is painful. If the AHA wants to improve the currently low mead entry numbers they should, you know, actually make steps to encourage them.