If you run Novas you can need much less gravy quanta running the deck with this combo: Voodoo + 3x BB + Freeze + 2x TU, so you only need 1 upgraded card (Voodoo).
You need 1 RT in case you have a last-card catapult.
That sounds like it would be good, but that is a seven card combo, and along with the RT that will be saved until the very end just in case, that's eight possible hand cloggers. That's the situation that I've been trying to avoid, since Limitless Speed, while it is amazing, has some annoying moments where you have to discard something just because all the other cards are combo cards.
(I'm not saying Limitless Speed sucks, it's great Chapuz
)
I like the idea of using RT, but then I would have to completely change the combo to fling actual creatures instead of Titans, maybe I could fit in a cheap creature like an Ash Eater to RT.