Okay, I have played around with the Caecilia font that I extracted from the KPW. As noted already, the KPW itself modifies the Caecilia font using some behind the scenes style sheet giving it more weight and and increased line gap.
I have added weight to the font to increase its readability at smaller sizes and where the frontlight is used at higher levels.
I am not using Font Creator since there is no version for the Mac, but have Fontographer and added 60 em to the fonts. I tried playing around with separately modifying the vertical and horizontal weights, but ended up with results that were unsightly and very hard to fix properly for the KPW.
For technical details:
-the extracted Caecilia has a WeightRatio = 7.21
-modified Caecilia has a WeightRatio = 5.78
-extracted bold Caecilia has a WeightRatio = 6.21
-modified Caecilia has a WeightRatio = 5.1
I have also modified some of the glyphs individually after weighting to improve readability at smaller sizes. For example, the "r" often touched the edges of other glyphs like "n", which could be confused with "m"
I actually like the smaller line gap that resulted from the extracted Caecilia fonts so I did not have to change that at all.
It was interesting with the line gap changes, that the heavier weighted Caecilia at size 3 shows just as many words as the built-in Caecilia at size 2.
Legend for attached photos:
Built-in Caecilia font that comes with PW at size 2 = Caecilia_Size2.png
Extracted Caecilia font that is NOT altered in any way at size 2 = CaeciliaExtracted_Size2.png
Modified Caecilia font at size 2 = CaeciliaMod_Size2.png
Modified Caecilia font at size 3 = CaeciliaMod_Size3.png