Thx Kovid, good spot.
Re the line-height/dropcaps thing. I've not got a lot of love for dropcaps
. Probably because I don't believe my Kindle supports them, and I also don't think that webkit/Sigil or whatever renders them "properly" either. So I personally have no issue of obliterating the "drop" by removing the line height and turning it into a large first letter.
I can appreciate however if you wanted to keep them then fair enough you would not want to run this option. What I had more in mind was some of those really nasty pdf scans into rtf which have hundreds of styles (and certainly nothing as fancy as drop-caps!). Maybe this is the wrong solution for that and I should just stick to Sigil regexes.