This would require tearing down his ENTIRE operating system architecture. Everything time-based (so, basically everything) is based on that rate. If FAS was going to do variable rate, it would have happened in the beginning. Now, it's such a core component of how everything runs, there's likely no way to change at the system level now. No one in the world would want to knock over the house of cards built over a decade+ and start from a clean sheet.
Unless he's been working on it the entire time, it's probably not possible at this point.
Integrated mic pre's would be cool especially for micing up acoustic guitars. That was a nice feature if the Eleven Rack (even if it was only just the one). Surpised it hasn't been seen elsewhere lately.
Now you're asking FAS to design specifically to design and write code for macOS and PC's which are so wildly variable that you cannot account for every compatibility issue that will inevitable crop up due to the configurations and capabilities of each individual's system, as well as the billions of different ways Microsoft can trash the works with one of their infamous updates, driving their customer service lines red hot and driving htem bananas for a decade. They tested the waters with the Reverb plug-in and it's no surprise to me that they have not gone neat that market since and probably never will.
Designing to open standards like MIDI is likely as far as you'll ever see them go.
Although you have a point on the Windows update possibility of screwing the pooch, requiring bug fixes and firmware updates, you can guarantee OS X will change to the point once a year where every software developer you ever said hello to is emailing you begging you not to update your OS.
On that note, throw into the wishlist IV ring:
Quality mic pres
Far better customization and control of block names and fx type names
A build your own fx editor like Eventide’s vsig
DAW mode giving you a known fixed latency figure
IO of at least 8 analog and 8 digital IO
A port for expansion cards, future development.
Unless I’m really missing something, an impedance matching feature much like the UA Apollo would be awesome. I admit not fully grasping this concept from amp to amp, but doesnt/shouldn’t this value change? What if the first item in my signal chain after my guitar and cable is a Fuzz or a wah? Wouldn’t that be different than a Mesa MKIV amp? The Apollo mic pres claim to physically change impedance values based on plugins in the first slot.
Bluetooth or network connectivity.
Not just profiling, but game changing profiling taking hundreds of measurements requiring hours of work, but resulting in a brand new model, not just a profile of a particular amps setting.