Exported design looks different than within InDesign
I created some artwork all within InDesign and when I export it, the output is significantly different.
InDesign screenshot

Acrobat screenshot

This happens regardless of the export format (eg also happens in jpeg & png.)
PNG

What is a little intriguing, is if I change the resolution of a jpeg or png export, eg to 72ppi, then there's still an issue, but it's different:

It seems like the effects are not scaling properly when exporting, among other issues. The issue also occurs if I copy the artwork out of InDesign and paste it into Illustrator.
The blue curve you see most pronounced in the last screenshot, conists of a single stroke, 100pt thick. I've then applied a gradient to it, set the blend mode to Hard Light and added Basic Feather to it.
