Well, I havent been changing the preferences default. I've been changing the setting
in the conversion screen.
And its not a matter of tweaking it until I get a "good" result.
I have never seen any result. I've never seen the unwrap heuristic have any effect whatsover on anything. And I've tried settings from 0 to 1 in .1 increments.
If other people werent assuring me that it works for them, I would simply assume that the
unwrap heuristics code was simply completely broken.
Actually I've never seen any of the heuristics have any effect on anything.
But I have the ticks set for heuristics and unwrap heuristics in the conversion screen.
I don't suppose theres a setting somewhere that says "never apply heuristics even if its enabled in the conversion screen".
Because thats about what I'm seeing.