Hello,
There are 4 more suggestions, I am going to change the name "2 suggestions" of this topic by another one.
The ratios for the canvas have been added with the idea of the quick access of A4, A3, ...
When Black Ink will have layers, the file extension will become necessary.
I am agree with you for autosave and to recover a file it is really usefull.
For the moment we integrate basic features, this feature will come later.
To keep the steps of your drawing, I think it could be interesting to make a saving+01.
For example you have named your image, "montain.png" if you do Ctrl+Shift+S you create automaticaly a new file mountain01.png, ... mountain16.png.
What do you think about?