I’m really excited about you coming onboard this project @verdeperto and find it much more fun to collaborate on these projects than go at it alone.
As I wrote in PM, I didn’t get any fruit from season 2025 unfortunately. I direct sowed 10th June. My other moschata struggled too, but did give fruit. In general, many of my crops produced much less than they use to and I attribute this to poor soil and lots of weed competition (first year turning what was just previously grassy field into a growing space). I am also growing them outside the city without the urban latent heat. My learning is I need to nurse the plants a bit more to get minimum 1-2 plants to set seed and start the cycle of adaptation.
Further down the line, after adapting to cool climate and short season, I think some interesting criteria for selecting would be firm flesh, more aroma (cucumber, melon) and lack of grainy texture. Personally, I really love the super-long necked tromboncino types, but long-necked butternuts are a good step on the way.
One limitation in building on butternut-genetics is that they haven’t been selected for immature eating. Tromboncino and zucchetta types have. My highest priority is northern adaptation and long necks. But it is worth keeping in mind.