Tesla's new 4680 cells would be great on an Alta. The higher energy density would help, but the tabless construction allows the heat to be effectively dissipated from the top and the bottom of the cells. Thermal management is now, well, manageable.
There was some talk about going open source with the Alta components. As far as I'm aware, all of the individual components that make up the inverter, ACM, BCUs, etc. are commercially available, and all of them have open source software. What Alta did that was amazing was package all of these components, design a motorcycle that works well with all of those components, and then create the software to make all of those components work together.
In theory, someone could start over with the software. Wipe clean the components, load the manufacturers' software, start over. All of this is out of my reach. I think there might two or three people on this forum that are capable of this, but who has the time? Even if we raised $100k, it's still more than a years work. And why? There are less than a thousand Altas out there. Hell, they made more DeLoreans than Altas!
I still think breaking Alta's encryption is the path of least resistance, but again, I'm not capable, as nearly all of us here are not capable.
Maybe someday we can make a Tesla cell powered, 100 mile range, 75 hp Alta. I'll definitely keep mine, hoping for that day.