Probably a good place to start. If KDE4 displays them at a decent speed on the same hardware, dissect KDE4, since its structure is still going to be somewhat more like Trinity's than Gnome.
Another possibility would be to do some sort of prerender-and- cache-as-raster, although that's probably adding needless complexity to the system.
Or we can just hack the Kicker code to discard all libreoffice*.svg files and drop to the raster versions--crude, but doesn't require cooperation from anyone else. We then ship a prerendered set of PNGs matching what LibreOffice was using at the time of release, and call it good . . . and hope that no one else decides ridiculously oversized icons are a good idea. :-/
The LO 4.1 package I'm using comes with png files of the svg icons.
As png files are already installed, then a short-term hack could ensure the svg files are not used.
Long term, update the algorithm.
I don't think they're likely to change the icon set with every update to LO, so we can just check and update whenever *we* make a new release. Only a few people are likely to notice or care (unless this also affects another DE's default icon set).
The icon graphics likely do not change often. Just the file name of the icons, which use the version number.
Darrell