Mine and my mates didn't feel any softer, we both followed each other to watch the rear end to see if it was flexing more and we both couldn't see any difference. I also have go-pro footage of just the board working and you can't see any extra flex.
Sounds good. I would like to see your videos.
But honnestly, by "hand feel", i pushed before and after the cut and i feel it is considerably softer...of course its hand feel, not very scientific but not completely unrreliable.
I've seen a company called coda snow board add a cable between the tips to help "spread the load" wich sound logic from the description on the website.
Coda Variable Flex
That said i have two ideas, one inspired from coda boards...add a stiffener bar made of fiberglass . The bar would be easily removable and would help the board behaving more "normally"
The second idea would be to laminate a pieces of thin plywoodon the end of the board. That would required a lot more work, glue, fiberglass etc.
See pics of my ideas below