Yes, all of what DR said, plus I have a few other suggestions:

- they can build in to tall stacks quite quickly on the rape, once they've filled out the bottom brood box stay well ahead of them on space. Also, I find it easier to have them closer to the ground for stability.

- to get the most crop plus filling up your empty hives, let them build on multiple brood boxes, aiming to harvest honey from brood sized frames and split the hives down at petal fall (once petal fall has started dont hang about, rarely will you get much more osr honey even if large patches of the fields still look to be in flower, also, be prepared for the bees to be a bit tetchy, the sudden stop of flow can leave a lot of bees grouchy)

This is my plan anyway, good luck