rock whool and flooding question

I had a quick question on rock whool cubes. I know your not suppose to put them at or below the flood level on a flood tray, but does it matter if there below flood level if it's just the little starter plugs? I wouldn't think it would do to there isn't much there as if it was a 4x4 or 6x6 cube. The little starter plugs wouldn't hold enough water to hurt the plant would it?

i water mine with a turkey baster you really have to watch rockwool as it retains moisture a long time i flood 6x6 with mat 7-10 days the little clone cubes i pick up every day if they feel light i water them [the light ones only] so-far so-good