Now again, if you select the "Held" option for a RealTrack it will play the Holds. You can also easily adjust the strum speed by selecting all the items on the track then right click Item properties and change the Playback rate.
You can't do this with a consolidated wav file.

Watch https://www.dropbox.com/s/ec12rtzjibw67j7/Reaper-Biab-Track-Injector-Held-StrumSpeed.mp4?dl=0

Download Reaper-Biab-Track-Injector-Held-StrumSpeed.mp4