Well, honestly, I kinda cheated.... hehehe
I actually wrote a lot of material for playtesting. While all the Cultures I made, and all of the Skills are in the base versions (Bare Bones & normal versions), I have a playtest version that contains more races, more Training Paths (and more spells, of course), a few more Combat Moves and Styles, etc..., more creatures, rules for herbcraft and alchemy, etc..
I could actually release some of this in multiple formats....
For example, that Casters Compendium, and Combat Compendium, and then still release the individual TPs (and ancillary information) as individual PDFs as well.
A Casters Compendium would run about 60-70 pages easily, and that is if I put in all 18 spell-casting Training Paths that I have (11 Casters, including the 3 in the core rules; and 7 Hybrids, including the 2 from the core rules).
And that would leave me about 25 Training Paths (that do not case spells), that could be in the Combat Companion. I have a total of 97 Combat Moves (only 68 in the core rules), and and 12 Combat Styles (7 of which are in the core rules), that would need to be included.
And then I could do a Creature Compendium. I have 57 creatures currently (31 of which are in the core rules, but I have a bunch more that I still need to write up as well).
And then still release various TPs (and ancillary rules needed) as individual PDFs as well....