I would think that a momentary loss of power wouldn't be a big deal, even with active cooling and a vacuum pump. As long as your disconnect is fast, if it takes

I would think that a momentary loss of power wouldn't be a big deal, even with active cooling and a vacuum pump. As long as your disconnect is fast, if it takes 500-1000ms for the pump and cooling to come back online from flywheel power, that seems like a much easier solution than worrying about five nines. The wear in that second can't be significant.