Freeship problem with splitting transom horizontally

Hi,

I'm looking at building a simple slightly stretched Weta-ish type trimaran for mainly single handing but occasional light 2 handed.

4.75m main hll with 4.25m floats, and a reasonable amount of freeboard as I am in the Solent and it gets pretty choppy and I want to do some longer coastal/camping type trips. Plan is to make it folding as I need to be able to trailer it and single handed put together, launch, sail, retrieve.

The problem I am struggling with currently is the transom. I have extruded it and it has no leakpoints so all good there but what I want to do is where currently the transom slopes forward I want to split it in 2 so the bottom part is vertical for about 30cm then the remainder will slope forward. This will enable me to get the rudder mounted nice and easily.

When I try splitting or anything it Just goes to pot and it shows developability going badly wrong. I've tried taking the transom off then splitting the hull side but even that causes issues.

Any ideas how/if I can do this? If not I can simply leave extra on the panels when I cut them so I can do it manually.

Looking to start building in feb at some stage I hope. I would quite a like a Weta but not many 2nd hand ones around and the last I saw was about £7500. I should be able to build this for £1500 tops as I already have sails, masts and foils etc.

I've attached pics and the .dfx files if anyone can help - best if it can be explained so I know what to do next time - hopefully I donlt need to split the side hull panels completely?

All help gratefully recevied.