Hi Kovid,
Converting .lit to .lrf in 6.3 (I've been using 5.13 up to this point), I noticed a couple issues:
First, I'm no longer able to control the indent spacing -- I tried both the "Minimum para. indent:" setting, as well as putting "p{text-indent: XXpt}" in the CSS Override section. No luck.
Second, I noticed that the centered text is no longer centered.
Mind you, I'm not ruling out that I might have messed up some setting or another along the way
but I haven't really played with any of the features as of yet.
If you need, I have the source .lit file, the new .lrf, as well as the old .lrf I converted under the previous version of calibre for reference.
Of course, if this is something you're already working on (or if I've messed up somewhere along the way), please disregard.