Hi Mark,

Just to chip in, one work around that I use is the 'IncrementalSave' command where it saves your session at that point and places a number after the file name and you continue working until you decide you like to save again at a point after adding features etc. in this way you sort of have a history of files you can go back on and use copy and paste between them if you've modeled a certain feature you want to use on a previously saved state.

To use the IncrementalSave just place the command name in the keyboard shortcuts and assign a key combo to it, eg. I use Alt+s

-