If someone wants to give it a try, here you have a modified ADE for Sony PRS-600:
http://tmp.pepak.net/hack-epubfonts-...ebug_only!.zip
I extracted it from the hacked russian firmware (
http://translate.google.com/translat...D12146&prev=_t) and did the same modification that worked for PRS-505.
Note:
I don't know if it works. I don't even know how to flash it back to the reader. If it breaks your reader, I don't know how to flash the original firmware back.