reduction in volume is not terribly important.
Think about the transport use case, post POSs:
- You move RAW moon goos you need loooong distances to your reaction farm/citadel, all of it.
- You shove raws into your refinery slots and watch INTERMEDIATES drop out the other end.
- You then scrape it off the floor, turn around and shove it into another refinery slot and out drops ADVANCED materials.
- After you FINISH refining it, THEN you think about moving it to another structure for consumption or sale
So, if you setup an EFFICIENT reaction farm, then your movements of INTERMEDIATE materials will be ZERO or very close to zero compared to RAW or ADVANCED materials. The only edge cases I can think of would be cartels trying to control critical materials and industrialists who buy intermediates to fill holes in their stockpiles.
This change would have been more meaningful while POS based reactions were active, but since it all happens in the same structure, less meaningful.
This change will benefit the small industrialist the most and have zero effect on the large industrialist.