There is a very high execution time difference between extracting M7 and KF8 part.
Creating MOBI7 from 373MB MOBI file (KindleGen output) take 2.34200000763 sec.
Creating MOBI8 from this same file take 103.877000093 sec.
Entire time difference is caused by insertsectionrange
function. Extractly by lines:
Anybody have idea how to optimize that?