First i would say i don't craft, but i know plenty who do. I also know a lot of people who want skill to matter when melding.
So I think they should add stat caps on for each tier of meld. If your going for dbl meld the stat cap is like 280.(not sure what crafters stats are like @ 50 and do not know if this is easy to obtain atm) every 3 points would add an 0.5% to the 25.7% chance you have already. So for an triple meld the stat cap could be like 310, and every 3 points over that cap would give you an 0.8% chance. So here is an example below:
25.7% Chance to dbl meld an item, but with 310 Craftmanship that would be 30.7.