"I would like to make the whole PCB larger by ratio of 1.5 (150%)" Exactly what do you want to increase by 150%? * The linear dimensions? * The area? * All the track widths? * All the track widths and lengths? * All the track spcings? * All the footprints as well? Please explain in more detail. Give examples of what you want to achieve.

You need to re-place the object at new location, change the board outline manually, doesn't like the PS tool, you can't resize them whole in same time