[Tomker]

My best bet is that the 25% weight reduction refers to the 30 lbs of spare parts that each team is allowed to bring to each event.
Since FIRST is trying to get all areas into the district format, more and more teams are going to atend multiple events, it means that more teams will be able to make big changes/upgrades between each event and they probably want to prevent it from being too big of a factor.