If there was ever a boat that should have come with a factory bracket, this is it.
With the tall transom wings, the splashwell holds it all together as WM said. What ever you do has to keep those wings from flexing.
I would think about reworking the transom into a more IO look so the plywood fits from side to side, weld filler AL to close the big U. Add outboard knee braces and cover the top with a gunnel to gunnel panel like WM's Chief and sliding doors or a curtain to cover batteries, knee braces, etc.
My thoughts anyway. Welcome to the Starmada, mkline, We'll help spend your money! :smile: