slow export for ktx files

Hi,
Unfortunately, there is no caching as it would overcomplicate export, e.g. we would need to handle cases when cache storage grows too large. In general, we recommend disabling KTX compression during development phase and enable it once you ready to go into the production phase.

here you go https://www.soft8soft.com/docs/manual/en/introduction/Texture-Compression.html#enabling_texture_compression