I think I recall reading that post/thread a while back, but I didn’t take it to mean that feature parity will only be temporary. Bearing in mind that at the time it was written, “next year” was 2014, I thought KB was saying that parity would take until the end of 2014 because (in effect) the Win version was chasing a moving target, and had to catch up with more than was/is currently visible on the Mac side.
I’m hoping once the current beta cycle ends (or the feature set stabilizes) the Differences Between the Mac and Windows Versions post can be updated, maybe with a matrix display of differences, if that’s practical.
After about 5 weeks of more or less non-stop use of ScrivWin, I don’t find features that are missing so much as implementations I’d like to see tweaked – though not a lot that full keyboard, toolbar, and menu customization couldn’t overcome. With feature- and function-rich programs, especially those used in creative work – and even more so as they reach a certain level of maturity (which is not to say age, but feature-inclusiveness/completeness) – the customization system becomes one of the most important features.
This is the first time I’ve been on the “lesser” side of cross platform development. It could be worse. 
With the possible exception of finding a great deal on eBay or a similar type of hand-me-down, the Apple ecosystem would need to pay me by the word (not against royalties) before I would consider buying in. 