We have static image property with 83% hit and 70% bandwidth offload, which is fairly low for static content serving property hence attempting to improve it.
As we already configured the property to have 365d cache validity for all images, first target was to close gaps between hit and bandwidth offload.
I have engaged Akamai professional service to enable etag support for the property as well as took out Cache-Control & Expires header from origin response as advised by PS engineer.
Which enabled 304 response from edge however it still sits close to NIL for origin response as below:
Hence we are not getting any bandwidth savings from the change. It also seems Akamai PS engineer doesn't have clear answer for why this is happening.
Only notable different of this property is having advance XML override for modify-host-header. Is this the culprit?