People normally associate WebGL with 3D game content, but it's for 2D too! I decided to build our own GPU rendering pipeline for the performance and document size benefits you mentioned and also so we can guarantee top-quality, consistent rendering across platforms. A GPU rendering pipeline is actually a pretty normal technology choice for a cross-platform desktop app. It hasn't been too hard to find people with that expertise to work on the editor. We're looking at people with game development or browser development backgrounds.