Could this be an option? just like the ‘reconfigure’ button one gets with several audio engines, rescan for available devices while renoise stays running 
Get Renoise for Mac OS X. 
Yay, unfortunately this is not possible on Windows. See for example Rescan Midi-devices on Windows please.
@EHVAH: damn you should’ve used the forum search
Bah. I came here to ask for this also. Suckage.