Hey Mike,
the traditional Z-16 Z assembly (on Machinist, Woodworker X-35, Woodworker X-50, and Journeyman) always allowed it to drill holes into your machine bed, since it can be attached in three different height positions to the X carriage, as shown here:
The new Z-20 Z assembly now, which is higher and has now 165 mm Z travel (compared to 133 mm on the Z-16) was introduced for the Elite Foreman machine because this machine sits not on Y-35 rails, but on Y-50 rails wich are higher, and the Z-16 would not reach down far enough. The new Z-20 Z assembly has now four different height positions in which you can attach it to the X carriage. I would assume that in the lowest position you can reach lower than the machine feet, just like you can with the previous machines with Y-35 rails and Z-16 Z assemblies.
Since neither I, nor anybody else yet owns a Foreman machine, it’s up to @onefinitycnc to give the dimensions. There is already a thread going on here that tries to guess the Z-20 dimensions.