Nice work Ken, FWIW I have a quick/easy (not so elegant as yours!) solution that we use to convert the twins into a queen; a piece of OSB cut to span the aisle with a couple of extra inches/side and a crib mattress thrown on top! Fits perfectly. I push the OSB under one of the mattresses and put the crib mattress on one of the beds when we get up in the morning. Makes for a little shuffling (not much) but allows us to retain the original layout, nightstand, under-storage...etc.