It seems that crafting is completely useless for end-game players (i.e. you can't craft anything at max PL). 

For me character appearance is a big thing. Why not allow users to have the artificer skins on the Relic level gear?

If that doesn't work, here is an idea anyway, why not replace the Mark I with "Scythe", Mark II with "Thule", and Mark III with "Koschei". Add a Mark IV as "Mars" and then you can even link them up with the current bonuses!

That, or you could add those modifiers on top of the Mark levels to make them relics or whatever.

I am just thinking out loud here but all relics shouldn't look the same. Relics, by definition, are usually one-of-a-kind.