I haven't tried doing it that way. Would you mind sharing how it works and what the advantages are?
As for the advantages, well, I'm not sure. The only advantage of the editor itself is the support for dxt4, and I don't even understand why it's needed. Textures with CONVERT_TRANSPARENT_ADD in their ConversionType must be exported only through the editor; otherwise, they will be displayed incorrectly (mainly effects). I only export finished textures through the editor, textures that I don't plan to edit further.