This post here: A very cool image tip! gives some very interesting ideas on how to reduce image size on rendering which speeds up things a lot.
In my case wherever I have an image showing I have added the optimisation parameters that imgix uses after the image magic text with the appropriate parameter for the size I need (2x the image size in Adalo to accomodate retina screens). So here I am showing a profile picture that’s 150px wide in Adalo:
