I have an idea you might want to use to get editing done faster: crowd-source it. Set up a private wiki for beta-readers where they can read the novel beta and edit grammatical errors. Would be even better to allow that on a per-paragraph basis.
Beta 2 has the first true editing pass, plus things caught by demons up to that point. It is still far from perfect though.
Done a few more since beta 2.
I am paying for a professional editor to do technical editing after beta. So in many ways the big “editing” goal for is to catch editing errors that a technical editor wouldn’t catch. Subjective/Questionable editing things.
Such as when one weirdly named character is accidentally talking to himself rather than the person in front of them. This has now happened at least twice in the book!
The whole Fierdy business, people out of character or speaking to someone not there. Grammar/syntax that is imprecise that confuses the readers; not so much technical English but as in: it looks like he/she is saying this to so and so, but shouldn’t they be addressing X instead, or similar things that require one to be immersed in the story to catch.
Obviously though, technical editing is also great if people can manage to catch and report them. This is because no single editor is perfect, even the professionals. I still find editing issues/typos if you will in big name author books from the big houses, and they have an army of editors.