What's Zoro's greatest strength feat so far?

[Warmmedown]

Cutting his way out of a chimney while barely able to move was pretty big.

His jump vs Pica too. Maybe it's strengthened by Toei making things last longer to fill the episode:

 

[SSJ2]

Probably cutting Kaido. It takes close to Yonko tier strength to manage that.

 

[Future Warrior]

Probably cutting Kaido. It takes close to Yonko tier strength to manage that.

Either that or blocking Kaido + Big Mom's combined attack for 1 second.