why something new? why not something established?
- It does exist,
to be actually incorporated in the ISO standard as well as the ASA linear scale,
- is much more convenient with these high sensibilities,
- and as said it gives a more sensible approach, stating clearly that the step between 25 and 50 is the same as the one between 51.200 and 102.400.
The APEX version with unity steps, giving directly a number of f-stops, would seem a bit more practical that said.
If the choice of the ASA scale is a matter of "God bless America" vs. "Deutchland über alles", one could pick the APEX then.