Covering the screen top of the enclosure will help get your ambient temps up as well. You can use plexi glass or something like that. Or you can use cardboard wrapped in foil. Just cut a piece of cardboard to fit the screen. Then cut out a hole a little bigger than the heart lamp, wherever you want to place the lamp. Then wrap the cardboard in aluminum foil. Wrap it tight and tape it well with duct tape. Lay it on top of the screen and the foil will reflect heat and humidity back into the enclosure.
Oh also, as far as the wood "hides" are they heavy enough to fall and injure the snake? Because I'm guessing the will be moved around and knocked over and may be dangerous to the snake. I suggest getting proper hides. If they cover a good portion of the floor, that's ok, BPs spend the vast majority of their time inside them regardless of floor space.