MyDesignPlaceholder is a ghost design that contains only water. It is never used in a real experimental plate. It’s only use is as a placeholder allowing a NanoDispenser booking to be made in the situation where the block that will be used in the NanoDispenser experiment has been booked in – but not yet made.
As soon as the block has been made, then the booking should be modified and MyDesignPlaceholder replaced with the appropriate screen.
MyDesignPlaceholder is NOT a placeholder for an additive screen. These are made using the optimisation tool in See3, and will be available for selection in the batchload wizard as soon as they have been created in See3.