To accommodate this I add an additional piece of angle that runs down the center from head to foot and has a support foot. Pine boards are used to create a solid support for your mattress. The additional $60 charge for this version is for the pine boards. You are welcome to get your own and I will waive the $60 charge.
The other factor to consider is the alteration of the heights of head and footboard.
I like the idea that the footboard is flush with the mattress. The standard height of the bed is 7" off the ground. If you wish for me to make the footboard flush then please tell me the thickness of your mattress. Adding 7" plus 1" for bedding will tell me the height of the footboard. You may request the headboard to be a height of your choosing. 45" or lower is common.