Can crystal legends be used to make mythic legends?

Just add 4 sockets and go? Benefits you keep the set affix and the crystal affix, and you don’t use obsidian. Drawbacks you lose all legend affix on item. Is this correct?

depends on whats more important to you. I prefer keeping the one that is not available in crystal roll (those found in certain items only). but yeah good thing is you dont have to use obsidian