This is an interesting discussion among the Shell Folks who understand the wonders of using a shell model camper and all the versatility and space it offers...you (we) are a special sub tribe.
We have long slept cross ways, one up one down in our 2012 FWC Hawk.
We came up with a fairly efficient design Bench Bunk Table that stows well for travel and sets up in 20-30 seconds if you don't include slinging out the bed rolls.
Our preferred Luggage is plastic tubs and half tubs which stack exactly the height of the side benches....and thereby can slide under the BBT even with the bed made.
Our typical plan is to find our spot for the night, pop up the roof, put the tubs topside at the front of the attic, make the top bunk, and then make the bottom bunk......all done in time for the tea kettle.
In a serious narly wind storm en route to Baja one year we both slept on the down bunk parked in lee of a semi and with the roof fastened down. For serious long distance travel I often sleep solo "down stairs."
I will try to add some images as they may show the arrangement...may need to mail them first to another member as I am technically deficient.
David Graves