DEMO preset for fonts

Hey Emmanuel, so while I was thinking about my 3rd font, I thought about a peculiar thing: I can release demo fonts for people to try out the font, which will have limited chars and will be replaced into empty character or a logo.

Would Affont be able to create demo fonts quicker by setting up something like a category that can replace the ready made characters? Usually demos will obstruct the numbers, symbols, some even replace lowercase letters, and having such function can let me be able to distribute the font easier without having to copy and paste the same thing!

Thank you very much for creating Affont!