Microsonic doesn’t handle MIDI pitch bend, so unfortunately that’s not an option. But in future it may be possible with other playback devices, yes. At the present time there’s no way to edit expression maps in Dorico for iPad, so you don’t have any way to set this up directly in the iPad version, but if you have access to Dorico on macOS or Windows you could create an expression map and then use the project containing that expression map as a template for Dorico for iPad.