I would always build with FSPackagetool even while sim open, however it magically stopped working after core update and fresh install of MSFS. In addition, it always rebuilds the entire ModelLib - not just the net new .gltf and its textures I add. This introduces a massive lag in between builds and slows down my workflow drastically.
Please advise as to what I can do to get back to "normal". Not sure what created this hurdle.
Thanks in advance for your time.