Scott Morgan
It's not as nice as using several Reverb objects, but you can automate parameters in real time.
When you create a DSP, a global RPC is automatically created as well. You can create curves for each parameter you want to adjust and move through the settings by adjusting the variable tied to the curves. It doesn't work well for different sounds with different reverb settings at the same time, but at least you can change the global reverb over time.
So from the programmer's perspective, he is just tweaking a variable value.