In which case you might benefit from running @ 96k which should be less
than 1/2 the latency of 44.1k but also more susceptible to crash due to
resource over runs. Not sure how that would affect Qlab.
If the show is really important, I would seriously test & test again long
before doors open & be ready to fall back to something else. The best
sound in the world for part of act 1 & then a whole lot of silence isn't
nearly as good as average sound for the whole show:)
ra byn