Re: ?? Welding Fito fork legs ??
Should be fine, but depends on where you weld and how it's done.
Too much heat might compromise strength.
I have had no problems whatsoever after welding front rack supports to my Specialized HardRock fork.....fairly extensive weld area on outside of tubes.
If more is better, then too much is just enough.
If you can't afford it, build it yourself.