One thing I like about RPG Maker is that last project you were editing is automatically reopened when starting the program so you can easily continue the work. Maybe it's worth bringing over to Solarus?
There was an issue to reload the tabs after closing/opening the Editor, and Christopho has already programmed that feature (which will appear for the next release). It's here:
https://github.com/christopho/solarus-quest-editor/issues/131