To be able to store baked maps on disk (not inside the substance file)
I'm working on a asset that has almost 40 udims. When I bake the utility maps needed for all those udims (some needing 8k) my file size increases to 20GB+ because all the maps are stored in the substance file.
I'd suggest an option in the preferences where one could choose a seperate location for those maps so every substance (and autosave) doesn't have to be so large.
This would save time on saves and autosaves (right now it's taking 3+ minutes on a 20+ GB file) and would also make me save the file more often, which reduces time and work lost when substances crashes.
Mario Cada commented
Absolutely. And in every production pipeline you will use a version control system. This behaviour uses a lot of wasted resources because SVN, Git, .. always have to calculate big deltas before uploading it to the server.
With 4k texturing the file size increases rapidly to 1GB. Saving multiple versions uses unnecessary disk space because the base maps are saved every time (but remain the same). There really should be an option to link the externally imported or locally baked base maps: NM, Albedo, ColorID ZDepth, AO on the disk. This does not have to be the default setting, and may even include a warning. But the option should be there if you know what you are doing!