German capital sharp s as alternative

Glyphs
1

I wanted to do the german capital sharp s as you have instructed in here:
http://www.glyphsapp.com/tutorials/localize-your-font-german-capital-sharp-s

But, I heard many native germans don’t like it or don’t expect this behaviour from a font, so I’d like to include it as an option that could be set on. So default behaviour would substitute germandbls with SS.

So how would you then recommend going about this?

2

You don’t. This is not the job of the font, but of the text engine of the app that uses it.