some quick additions
800mm is a typo, the LW hull is only 600mm in beam, 40ft - 12.2m/20 = 610mm
a pilot berth needs to be accessible from the cabin somewhere
nav needs to be accessible to the helm and both ends of the boat, equally if possible

the philosophy here is that with money saved on provisions and hardware for a smaller boat, more can be spent on other systems
the intention is, this boat needs to survive on the hook, and so a water maker and a robust electrical system and electric drive are going to be important for self sufficiency,

but accommodating the weight is going to be the battle