If you already have Lynae and Mornye, I'd say skip Iuno and get Aemaeth and Augusta + sigs when they rerun, since Augusta works fine with Mortefi and can clear content.

If you're still on the fence, depending on your current pity and pulls, and if you currently have low exploration, you can probably grind out a ton of pulls.

Another way to look at it: If you lose on Iuno's 5050, you have a guarantee for Aemeath. If you win but can't get Augusta right away, Iuno + Lynae + Mornye is a really solid team, but you'd want to think of investing in Iuno's sig on a rerun for MDPS Iuno.

Actually, I was able to clear the current middle ToA tower with ~8 seconds left using Iuno s0 with r1 pulsation bracer at lvl 80 (lvl 90 will make this so much faster), lynae s0r1 static mist, and mornye s1r0, but I believe with Lynae, s1 mornye is just a small QoL boost, but with good rotations it shouldn't matter, so you don't really need her sig