In BikeCAD version 13, we have the option to specify a dropper post. Additional input dimensions have been added to account for the extra complexity of these posts. The Travel field is meant to define the total available travel. The Drop slider allows the saddle to be dropped and raised any fraction of the total available travel. The saddle height dimension will always show the actual saddle height for any given amount of drop. The saddle height input field will always define the saddle at its maximum height. Therefore, lowering the saddle by compressing a dropper post will change the saddle height dimension shown on the screen, but it will not impact the value defined in the saddle height input field.
Several RockShox Reverb Stealth dropper posts have been added to the standard seatpost menu.