First, if they are not tight for laying room, do nothing. If swarming is likely, due to lack of laying room, the brood nest needs to be expanded. With the cold nights still to come, I would not give them space within the brood nest, but rather adjacent to it.
I would do nothing to hinder heating the brood nest.
The pollen frame is the queen's wall. she will NOT cross it and lay on the other side.
With 6 frames of brood, that only leaves the pollen frames movable, without moving the honey insulation, or breaking up the brood nest. I would put the pollen frames where I wanted the new brood nest walls. Probably #3 or 4, and #8 or 7.
Clear as mud?