Using gears (or zoan/hybrid/awakening forms) probably taxes the stamina, We see zoans switching back to base many times even when you might think that they don't need to. While all zoans have three distinct forms, human, zoan, hybrid. But it seems Oda has left himself quite some room to do other things with this.
We know base Luffy and awakening (G5), but which of his forms is the zoan or the hybrid. Is the awakening of the Mythical Zoans their zoan forms or their hybrid is their awakening?
Regular Zoans:
Zoan, Human/Base, Hybrid, Awakening
Mythical Zoans:
1. Sengoku (Base and Zoan or is his Budha form his Hybrid or Awakening)
2. Marco (Base and Zoan and partial transformation, which one is zoan, hybrid and awakening)
3. Yamato (Base, Zoan, Hybrid, what about the similar clouds, is her zoan or hybrid her awakening)
4. Kaido (Base, Zoan and Hybrid, does he have awakening?)
5. Orochi (Base and Zoan)
6. Devon (Base and hybrid/zoan, can't remember which was shown)
7. Luffy (Base and awakening, what are his zoan and hybrid)
Seems like mythical zoans are just for Oda to do whatever the heck he wants (not that it is limited to just this when it comes to Oda), there seems to be zero consistency.