I was unaware that virtual instruments could 'Transmit' key switch info to Expression Maps (EM's). I thought they just received that information from EM's. That is, afaik, the purpose of EM's; you don't need to use key switches.
I know EM's receive Remote Key information from control surfaces like e.g. an iPad running Metagrid Pro.
I'm pretty sure Cubase's EM functionality does not include a 'Compile Expression Map' function. It would be nice if it did though.
Re: Iconica EM's, I haven't seen any floating around the web. I would strongly urge you to familiarize yourself with the EM building process.
BTW, I would also recommend using 'Attribute' rather than 'Direction' in the 'Articulation' section of the EM builder. It makes working with MIDI and libraries like Iconica much easier.