So the reason for the delay boils down to shitty middleware. I would actually like Larian to explicitly call out the middleware in question in order to make it obvious to other developers and potential Kickstarter backers what kind of crap they should avoid.
I am happy to hear that Larian is attempting to develop their own cross platform implementation of whatever this unspecified middleware provided, as this means that possible future Linux ports of their games will be faster; we'll see how it works out for them. But until Larian can deliver something more tangible than promises I am going to be exceedingly wary of sending my money to Larian again.