Is the end grain of the internal wall ribs really sturdy enough for mounting the interior finishes? Especially if using OSB…
@Kasimirsuterwinter Depends a bit on the weight of the internal finish, but plasterboard and plywood seem okay with it. From experience you may need to use proper woodscrews rather then plasterboard screws (which are black in the UK) to really bite into the end grain. If you were intending to hang heavy finishes or shelves etc you may want to add standard battens behind (alongside or between the ribs) to provide extra strength.