In Windows, it appears that "Control-S" (Ctrl-S) doesn't work in Logos Desktop. I would like to suggest that "Ctrl-S" be assigned to "Update current Layout". I don't know how many times I have changed a layout and then automatically hit "Ctrl-S", automatically thinking I have updated the current layout... only sometimes to find I didn't. 
This works in just about all files to save the current file, if the file is editable. Just a suggestion that would help I think.
Thanks. 