When referencing help in Mosaic Designer v2.4.0, I noticed in Quick Start / V1.x.x to V2 Conversion / What's Changed, there is an interesting line in the General section:
"Auto-save – your work is stored to disk as you go"
I have been unable to find any more information on this. Running a few tests, I see no evidence that Designer saves as you go. Does this feature exist, and if so, how do you enable it?