In the 3 pictures (low, normal, high), I was adjusting the height via the factory dash switch. The kit I made will alter the height across all 3 settings.
For example: if you set the kit to run about 1" lower then stock, then all 3 factory settings (via the dash switch) will run 1" lower then stock.
For example: if you set the kit to run about 1" higher then stock, then all 3 factory settings (via the dash switch) will run 1" higher then stock.

If you do not have a factory dash adjustment switch, then the kit will just lower or raise the height for the systems only height setting.

As for the limits of the system, the "low" pictures above is the lowest the factory system can go due to the limits of the factory airbags. I have my truck setup so that this "low" height can only be used when I select the "low/access" mode on the factory dash switch. This "low" height is way to low for normal driving because it is running the system on the "bump-stops" and its really bumpy with poor handling.

Also if you set the kit to run the vehicle to this low position while in the factory "normal" position (middle position on the dash switch) then you will not be able to use the factory "low/access" position (lower position on the dash switch) because the system can not go any lower.