Your concern is certainly valid.  Simply Fortran always opens the file selection dialogs in the current directory, which is not necessarily the directory where your project lives.  The original idea was to allow Windows to manage the current directory per its own default behavior, but I don't think the way Simply Fortran works right now is ideal.  I'll try to get a more sensible solution for the next version.

I've noticed - if I have understood correctly - that saving a source file using "save as" seems to save it under the new name assigned to it by the user, not necessarily to the same directory as the original file, but often to somewhere else - I'm guessing to whichever pathname was last selected expressly.

This seems rather dangerous.

When I'm about to embark on a lot of alterations to a complex subroutine, I have tended to use 'save-as' twice in succession, once to rename it as 'filename.bak' and once to re-rename it back again to 'filename.for'.  I have been assuming that the .bak file and the .for file were saved in the same source files directory as all the other .for files.  It doesn't, but this is not apparent because all one can see is the same files list in the Project Outline panel.  Then, from outside SF, when doing a cleanup, I've found files in the 'wrong' place and manually deleted them, in the incorrect belief that the latest source files I've been working on are safely tucked away where I thought they were.  I've lost a bit of development work as a result.

I'm now more careful, making no assumptions about where stuff is being saved, but I wonder whether this was the intended behaviour of the editor.
---
John