Clever solutions. Thanks for sharing.

I use tape instead of screws. Then I just slice through that tape before stripping over it.

Also, I find it easiest to make inner stems from a few thin laminated strips of soft wood instead of carving a single piece of wood. The laminated strips generally conform well to the required shape with only attachment in a few places. The photo below is a canoe, but you can get the idea. The holes allow clamping of the laminated strips until the glue dries.

John