I did something similar on March 8th, placing a medium between the two deep supers. However the honey was in the top and the bees in the bottom. I had no drawn comb so I used plain foundation. Unfortunately this colony is very slow to decide to draw out comb on plastic foundation, ML PF120, and i believe they started eating the necter stored in the bottom super. They developed dysentary about a week later and it lasted until I pulled the medium out and reinserted it on the top. I checked April 4th and they were doing good. The medium is still not drawn, I plan to leave it where it is and let them draw it when they need it.