Does compressing your sprites before importing them into C3 make a difference?

Does compressing your sprites before importing them into C3 make a difference? I know that C3 compresses them when exporting, but is that as strong as an external 70% png size compressor?

All PNG's are run through PNGCrush:

construct.net/tutorials/construct-3s-export-optimisations-4

If C3 is anything like C2 then it was always the case that all images of any type needed to be fully uncompressed on import before they could be used on the canvas, so compressing before importing is a waste of time.

Compressing images is only of use at reducing the downloading time, not the rendering time.