Hi, on my ipad the Model D is cut off at the bottom, can only see half the keyboard, and I can’t resize it, not sure if I a missing something but I have seen a tutorial video where you can see the whole instrument
there is a toggle to the lower right of the synth’s dials and switches. When you switch that toggle it shows the full height of the keyboard and the plate of knobs to the lower left side of the synth’s interface. These are the side knobs found on the hardware synth below the main panel of knobs in a small box to the left of the keyboard and there you will also find the toggle button for decay (release vs hold in some synth terminologies). These are pretty important settings. For instance it includes the volume knob. This scene shows the keyboard. Just tick that toggle below the filter and envelopes in the wood area when the keyboard is half height.