I just cooked a 800gr tomahawk steak with bone, i cut it to lenght first to fit my seled bags, then cooked in a polycarbonate box i cut the profile of the anova in the lid to avoid using any clamp or anything. It just hangs on the top. Plenty of space to cook it there. I gave it 4 hours but was frozen, if you dont like the meat to release juices but still be pink, add one hour.
Meat cooking time 3:30
Add 30 min because frozen
Add 1 hr if no messy juices when cutting
Mine was fine, i presliced (not all way through) on a chopping board, waited 30 seconds so most of the fluid are gone and wont mess with the plate, then transport onto a heated place where you will serve it.