Mine are always single spaced, and whilst I've never had a shock accepted I've had enough feedback on occasion to suggest a single spaced synopsis hasn't put them off looking at the script itself.
happy to know that they give feedback. I have submitted prose short fiction and know to expect usually nothing accept the notice of rejection and sometimes a request to send something else. but nothing in the way of suggestions for improvement.
Most of my rejections are the same, and Matt Smith doesn't always provide feedback, I've had some fairly generic 2000AD rejections, but clearly where he's seen something good in a story, just not good enough, he's been kind enough to at least explain why he isn't accepting, which is always really appreciated because form rejections can be dispiriting. It's especially heartening when you realise just how mammoth their slush pile must be.