If Iskall does end up adding stairs to his Omega Tree, he should add them in the form of carved-out vines! Link to more pics of my example build in the comments :
The Toxic Sludge Monster! - Hermitcraft 7: #62 - YouTube
Tutorial: Very Efficient Slime Farm (18,200 slimeballs/h) - YouTube
Hermitcraft VI 848 Breaking Iskall's RUN Game & Insane Leather Farm! - YouTube