Caching unchanged tables or glyphs

It's possible that a user constantly generates a font while they're developing or designing it and if a UFO file gets larger compiling could get slower. Since there are ways to track which parts of a UFO is changed I was wondering if this could be something to consider for future if ufo2ft could cache some parts inside the UFO like what makeOtf does (it saves the post-processed outlines inside another layer inside the UFO)? This will save a lot of time for developing fonts. Also if features are not changed and only an outline is changed; there is no reason to write all the features maybe? I know it's kinda invasive and huge modification but it also improves the design/development process dramatically.