Making a downwind board

Hi everyone, I’m planning to build a DW sup foil board. I would like to hear your thoughts on a few subjects.
1- any tips on making the board as light as possible?
2- foil box placement? and length, are the 16 chinook boxes worth it?
3-bottom shape, should it have hard edges or round?

thank you

Might be better to ask over here. Or just follow along with his build process. This guy is currently obsessing over his board weight. (But still uses an AXIS 19mm aluminum mast)

to be fair board weight matters more than mast weight.