Hey, I called it.
He crafted himself a better body, even if it is just temporary. Actually why isn't it permanent? He should be able to just do it. Is it just because the author wants to have a hint that maybe he isn't able to craft anything and everything, only to subvert our expectation and make him craft anything and everything?
Probably.
And of course he can craft himself an Unlimited Blade Works.
Though tragically, neither the MC or the author will be crafting a good story though. That would be too overpowered an ability for the MC. In any case, it's still an entertaining piece of trash to quickly digest as the ultra processed empty carbs mind numbing power fantasy that it is.
Also, page 15. I am mildly disappointed he didn't craft the evil jewel into a holy jewel. But we have already confirmed that Destruction is part of his Crafting set, he's just crafting Destruction after all and we should look at it in that specific way. He isn't destroying the jewel. He simply crafted the destruction of the Jewel.