That's a good cut and it will be difficult or costly to reduce the weight without reducing the number of items. This is for 3 or 4 folks, right? And does not include water weight.

Are you trying to get the entire kit to 20lbs? Just to make sure I'm not overlooking the obvious, what is the overall effect if you break your "heavy" bag into two bags, each under 20lbs?

If you're trying to get the entire kit to 20lbs, I do not believe that is feasible. Water (for planning) should be about a gallon/day/person (and that's not a rich ration). Figure 8 x 3 = 24lbs just for one person. 72lbs for 3 and so on...

What fraction of that weight is conventional food? Freeze dried is OK for a few days (I get fat-hungry really quickly) and the retail-packaged portions are a joke for normal sized adult males, but it really drops the weight significantly while retaining some familiarity and acceptable taste and texture.

Like Matt said, I could offer a better opinion for your consideration if you expanded the list some.

Going very far with weight reduction while retaining function is normally an expensive proposition. How about a folding pneumatic-tired cart instead? 300lbs is no big deal in most trafficable terrain with those.

I look forward to seeing what your final weights get down to - this should be fun (for us at least!)

Tom