It seems there is another one change of the Aalto factory/user presets location. In the v1.5 all the presets are installed in User Library (Mac OS).
Right now all the presets/folders which name starts by 'Aalto' are located in the top part of the Aalto preset menu (before the divider), and all other factory presets are located after the divider.
Now, what should I do to add another one divider after the factory presets (Alessandro's Machines... - ...Surachai) to store my own (user) presets?
I think of all the presets after the divider (Starting with Alessandros...) as user presets. you can get rid of these if you don't want them, or you can add your own directories here. Just click Save As... to save your preset, then make a new folder inside the Aalto folder.
The directories are all in the same place. Any directory staring "Aalto", will go before the divider.