Our group has mythic characters, with one guy having a pair of Legendary items.
He took Resonant Regalia, so has a legendary dagger (his +5 Vorpal) and breastplate (his Elven Chain +4).
The sheet basically has the name of the item, on the top few sheets, which we generally use for the character sheet.
It doesn't have the specials, unless you dig deeper and look into the extra 15 pages of abilities.
If Hero Lab was used as a character sheet, at the session, then everything is there on the mythic tab, the weapon tab and the armor tab (so three tabs in his case, but two for most characters).
The Resonant Regalia doesn't really work. If a second item is made Legendary, it doesn't like having a second one, as you can only name one in the Mythic drop down box. And apparently the scripting of Resonant doesn't bypass that.
Our group is fine with assorted red tabs, within Hero Lab, as everything is correct (as far as we can tell) with the actual build and using the books as a reference.
For our game, we're also using Mythic Hero's Handbook (available for purchase on the HL site, but made and maintained by a third party publisher) which is more moving parts to provide integration conflicts and such.
I'd add... in the "it would be nice" category, to have all mythic stuff print on a section of the character sheet print out (the top few pages) similar to the other "summary" information segments of the print out.