I ended up deleting the sense plugin and all of it's devices, including the plugin, preference file, and log from the Indigo folder within Library, and stopped/restarted the server before reinstalling..
Once I reinstalled, I'm getting the same error that @norcoscia got when he merged two devices: NameNotUniqueError. It's showing up for each device that was created. Further, each device that it does create does not show an on/off icon for, nor any power reading, even on devices that are current on and showing a draw within the sense app itself.
Looking at the plugin.log it looks like after creating all of the devices, it tries to create then a second, and third... time.
My Indigo log then gets filled with the same error over and over again every 90 seconds as per my specified polling rate.
I've attached the plugin.log from within the com.howartp.sense folder.