I did manage to record in BiaB using my EWI-USB
1-in Preferences /MIDI Driver set you MIDI input to your EWI
2-in the mixer/Plugins select a sound, either GM or a VSTi, in either the Melody track or the Soloist track. I choose a FM Piano for the Melody track.
3-click on the record MIDI button, select the track you are going to record to and press record. If your screen does not look like mine then click on CRL-T.

I would freeze all of the other tracks just as a precautionary measure.

Now the bad news, you can not hear what you are recording. After you save the recording you can hear what you recorded by press play.

IMHO it is better to record tracks in a DAW as you will have more options available to your. Things like more tracks for recording, hearing what you are playing while recording etc. If you don't already have a favorite DAW then learn RealBand; that is if you have the PC version.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
preferences.jpg (119.57 KB, 48 downloads)
VSTi.jpg (53.22 KB, 48 downloads)
record MIDI.jpg (30.4 KB, 48 downloads)

Life is short so make sure you spend as much time as possible on the Internet arguing with strangers.

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware