I did initially wonder about supporting other formats, but the immediate question becomes how would it work, when you have a book that has multiple formats? Say you have a book that has an ePub and a mobi version. Which would it choose to calculate on? Should there be a user configurable preference list (a bit like the input format order?).
And then if using the apnx code, clearly there is the two algorithms - should the choice be hard-coded, user configurable, or use the Kindle driver setting?
It opens questions I chose to avoid for the sake of a quick plugin that was primarily a technical experiment as a precursor to the new version of Extract ISBN...
That is not to say I wouldn't be willing to make the changes to make it more useful to others, clearly from the posts above there is interest. I just would appreciate some input as to how you would like to see it working.
For myself I only store ePub and mobi versions so always have an ePub to "calculate" on. I guess it will be interesting to see how the numbers differ on user_none's page calculations versus the simple calc done on ePubs for the viewer.