CTRL key, ESC and other functions (on both Win and Mac) are all supported on TextBlade.
This is configurable and re-mappable according to user preference, and the type of host.
For your case, CTRL is activated by pressing on the left corner of the SpaceBlade.
MultiTouch sensors in the SpaceBlade can detect different input signatures, so that CTRL can be easily distinguished from a space character.
This enables you to use your thumb to select CTRL while still keeping your fingers on home row. Very handy for things like CTRL A.
This is actually easier and requires less acrobatics than a legacy keyboard.