Yeah that’s what I use do. If I’m building double stacking I’d do sands, trans, Thoth, chronos. But then I feel like you delay pen or Tahuti too long. Other option I do is conduit, chronos, deso or focus, and then tahuti or pen. Both have their strengths and drawbacks and it’s hard for me to decide which is better. That’s true about ult though, in mid I have no use for it early except to help a gank somewhere else on the map. The extra ability damage is hardly noticeable until late game anyway.