Originally Posted by olandese
the plugin is also much faster with pdf than with chm files.
From posts I have seen elsewhere I believe chm is a difficult format for Calibre to handle, and is best avoided in general if possible if you intend to read the book anywhere but on your pc. This plugin just calls the same code to read the book pages in calibre that doing a conversion would do, except for PDFs which it was easier to put an optimisation in for. So any issue with performance I can do nothing about unless calibre is able to do it's part faster.