I still don't see what's wrong with just starting from 1.0 and increasing the number using the convention that increments before the dot are more important than ones after the dot. For purposes of marketing you can assign more flashy names and numbers too, but just one simple version number is easiest to work with in software.
Yes, that means that
if there is at some point a Pyra with an x86 SoC and then after that a Pyra with an ARM SoC again, you may have software that only works on Pyra 1.x and 3.x but not on 2.x. Or maybe it works on all of them because we use a fat PND packaging system by then that just ships multiple binaries. Or maybe it works on 2.x and 3.x but not on 1.x because 1.x is too slow.
The problem with trying to encode all relevant features in a version string so you can specify software requirements as a conjunction of mask + inequality clauses (as in "Works on Pyra A.B.C.D.E with B>2, C >3, D>0, E>1") is that it's hard to predict which features will be relevant in the future. How many features are there that you want to put in the version string? SoC architecture, display resolution, 3G/4G, gyroscope, camera, 3D display, UHS-II SD slots, flashlight, scent vaporizer, nano-USB connector, surround sound, tactile stimulation glove, direct neural interface? Should we pad the version string with a big series of zeros to have some room for future features?
How long will the name Pyra be kept? At some particularly big update, we may want to use a new name anyway.
I think it would be most useful to just have one single chronological number for all DragonBox devices.
For example:
Pandora Classic: 0.1
Pandora Rebirth: 0.2
Pandora 1GHz: 0.3
Pyra: 1.0
Pyra 3G: 1.1
Some future Pyra with a somewhat faster SoC and 4G: 1.2
Some future Pyra with a user-facing camera: 1.3
Some future Pyra (maybe called "Thuja") with a completely new case, can be used as a phone, with an extra e-Ink screen on the back of the lid: 2.0
Some future Thuja with a higher resolution color e-Ink screen, with touch too: 2.1
Some future Thuja with a faster, 16-core SoC: 2.2
Some future Thuja with 5G: 2.3
Some future Thuja (maybe called "Delfos") with a 64-core SoC and 64GB of RAM: 3.0
Some future Delfos with 128GB of RAM: 3.1
Some future Delfos with a built-in 4K retinal beamer: 3.2
and so on. You get the idea