QuiltMC (or just Quilt) is a relatively new Minecraft mod-loader project that aims to learn from the mistakes made by other mod-loader projects in that sphere. It's just entering beta now, and it already has a following - it'd be nice to see support for it both on the CurseForge site and the CurseForge Launcher.
It's worth noting that Quilt support both Fabric and Quilt mods initially, so ideally the launcher would allow users to install both to their instances.
Modrinth support for Quilt (beta's just beginning though, so projects are still being published)
Adding Quilt support should be very similar to adding Fabric support, both for the site and launcher. Of course, if the CF engineers need any help, the Quilt developers are quite happy to do so!