Dual Extruder Sensor Upgrade

Has anyone figured out how to add the optical sensor from the original extruder that was rigged up to the dual extruder yet?

I ordered the dual extruder and am not looking forward to losing my glass bed.

Also, does anyone know if flexible runs better on the new modules? I rigged up the spacer clip found some springs on mcmaster carr that work quite well for some of the flexibles, but the really soft stuff i just cant get right.