As for Iconics, with the advent of Unlimited characters, we eventually want to have an iconic library from level 1-20 for each Iconic character, which can be played in an Unlimited character fashion. There is also the rule that the first time you play, as an iconic/unlimited character, you can immediately turn the XP over onto a new Signature character (at least it used to be there, I'll have to check the rules). Per the Signature rules, the XP earned would be best equivalent as if you played it at the Signature Character's max level (in this case 1st).