Image Import size

eligames

Hi I have been creating my art in affinity designer and I import it into gamesalad. I have been making it 3 times bigger in affinity design and then scaling it down in gamesalad where I divide it by 3. This makes all the buttons and images much clearer and look nicer, but I do not like having to scale down every single image I put in. Is there anyway to make the size 3 times bigger and automatically have it sized down. Can I do anything in affinity designer to achieve this like change the dpi?
Thank You