I’m no longer using NWP, but I just launched it and opened some documents I had written in it in 2025. Everything seemed fine, but there’s nothing fancy in them.
I would never do my primary writing in Word. I’d spend more time screaming than thinking. FWIW, I now use Mellel, which does have equation support – how well, I can’t say because I don’t need equations. When I need to interface with people who require Word documents, such as publishers, the export seems relatively sufficient. I double-check it, of course, and I do find glitches that need my attention in Word. But even that it not enough to get me to spend my productive time in Word.