Oh,
I didn’t think about Creasing those Edges before the Subdiv. That’s clever.
Overall, this is an excellent workflow! Very elegant.
The Extrusion on X is okay, you could also Scale a Plane (in Edit Mode) time 3 on the X-Axis and times 4 on the Y and then CTRL+R, to get the 12 squares.
At 1:12, they use the Loop Tools Addon > Space. Very nice! Alternatively, you could Delete the vertical Edge Loop and CTRL+R to Add a new one, that would give the same result, only then you could simply Scroll up to get the correct amount.
And Omar is good, as far as I know.
