I don’t know of any technical reason why couldn’t work, or why technically it shouldn’t be done, but as I recall, whenever I bring up the subject of a complete in-engine toolchain, some of our lead technical artists on the HairWorks project push back vigorously. Toochain and workflow are largely a matter of preference, but our artists believe that much of the work should be done in the DCC plugins together with a dedicated tool like the HairWorks viewer. Not being a production artist myself (or any kind of artist really), I like the idea of having a complete toolchain in-engine, at least one that would let you do, say, 90% of the operations that the full toolchain provides. makes it much easier to introduce the to new people, demonstrate it, roll out new versions, etc.