The only explanation I can imagine is that NL's core business is something else, like Real Flow, and they just pull people off of that to work on Maxwell once in a while. That would explain why right around release time they are able to put out several quick patches for a few days, then it all goes quiet again, even when it comes to fixing important but simple problems- because they had to go back to working on something else. And they clearly have little or no organized in-house testing program. Volunteer beta testers are meant to be a backup, not the sole means of finding bugs.
Feversoft appears to be just a small handful of people. If you look at Chema's posts in the forum, he spends all his waking hours at work. And he doesn't sleep much. He's driven, obviously highly skilled, and 100% of his attention is focused on one product. As soon as they support my software, I'm game for trying it out.