Or move the mast, beam and boards forward and use a long pole. This has the effect of improving control (distance between boards and rudders) speeding up tacking, improving lift on the bows downwind, allows for longer sterns...... This is more of a skiff type rig. Try and sail a Super Wave to get an idea what it is like.

Designing a cat is like solving A+B+C+D+.....=14. There are a million combinations. You talked about one and I talked about 1. Never forget that when you change one thing, others have to change also.

For example, with a mid mounted mast (7 ft from the bow) . With an 8 ft boom, the back edge of the sail will be a 12-18 in aft of the sterns. Sail area with a 23 foot luff is 92-184 ft2 (triangle - straight leach) Center of force 9.7 - 11 ft from the bow. I found with narrow hulls you need about 2-3 ft of stern length to keep from dragging the sterns so you end up with about a 5-6 ft tramp.

I am not going to talk about computer modeling let's just stick to experience. Also you can adjust an existing boat (mast rake, boards up or down) to give you some feel for what these changes do. This used in the aircraft industry a lot.

The CF location is in the weather helm from hell territory -It is like a big sq top on a uni-rig with a LOT of mast rake. You are going to have to compensate somehow. It is hard to get the boards and rudders to balance. Under some conditions the rudders will load up so much it will be hard to tack.

Weight distribution You always seem to need your weight forward in light to moderate air. You are going to need to sit forward of the crossbeam balanced on a narrow probably rounded hull most of the time where I live

Spinnaker pole - You are going to need a long pole to get enough lift on the bows. This means the CF will be way aft up wind and way forward down wind

None of these problems is insurmountable. You need to be aware what you are getting into. I suspect that a boat like this would be near unbeatable in it's design range and very hard to control outside of it's design range. If I knew I would be racing 90% of the time in say 12-18 kts or 18-24 it might be the way to go.