In working on the startup speed of LibreOffice Portable, I've been considering how long it takes the Windows API to handle loading the fonts in. This process takes place every time you start LibreOffice Portable and the fonts are removed every time you exit. LibreOffice has bloated up to include 86 fonts as of 5.2.1. I'm not sure how much this is an issue, though, as I don't have a good setup to test on.
One option I was considering was letting apps like LibreOffice Portable advertise to the PortableApps.com Platform that they have included fonts that should be loaded system-wide. The fonts could either be loaded by the platform in their current location or moved from the app's font folder to the platform's font folder as the app is installed. This would alleviate the issue of the same font being loaded from two locations. Any time required to load the fonts into the Windows font list would then occur just once as the platform loads. Managing this process would not be too complicated (we can compare font versions based on the advertised FileVersion of the TTF files, for instance).
Thoughts?