LOL while I was taking the screen shot you were looking right at it.
I can drag export midi track in Reaper but also save as a single track or multiple to any folder.
Drag and drop just fills the folder up where as a Save option in the track's menu will allow you to save where you like and overwrite without creating a new instance.
You are allowed to save as a wav from the track menu, goes to reason you should have mid also.