I want to propose a thesis: Crafting of armours (and belts and rings) is basically useless.
Why? Crafted armours are "better" in two aspects than found ones: First, they give a bit higher armour than usually found ones and they have a slightly better movement bonus.
But here comes the problem: They have one magical property at maximum, and even if it was two properties we'd have the same problem.
A crafted armour that has 2 or even 10 points better armour than a found one and like 0.2 or 0.1 better movement bonus has a very hard time to compete with two or three +1 or even +2 to for a character useful stats.
I'd never trade the slight advantage for armour for the list of
+1 Constitution
+1 Perception
+1 Dexterity
on the found one for the Rogue.
And therefore: Crafted armours simply (and sadly) are useless. Or do you run around in armours that make up for the lack of bonus to the stats?
Or can you enhance crafted armours somehow with another stat bonus (e.g. from magical starfishes or whatnot)?
The same goes for belts and rings, I fear. Why would I ever wear a belt that has one bonus, while found items usually come with at least two?
Crafting comes down for me to Weapons, here the additional damage makes up for the lack of boni to stats and improving found armours. Which I find a tad sad.