So much effort has gone into group play but currently you either split loot evenly (and dramatically slow progression), or penalize everyone else and carry one member. ...which isn't fun in a game that revolves around progression. The obvious path and interplay of having members run down different parts of the tree is missing.
Stronger Together. There's a crazy easy fix: The team's tech-tree unlocks should be pooled when they are in group.
Half the work is already done: I have blueprints with unlocks from the playtest that I can't use. The system handles it fine.
The slightly less easy part of this to make it good would be to allow players to enable (up-to-date) tech-tree contributions for BP editing from players you've grouped with in the past so that you can actually build without people just waiting around sitting in a group so you have access to their unlocks.
The last stretch feature might be to iterate over friends list for their unlocks, and display who you know that could fill in missing requirements for each blueprint on the list. This could be tricky to make it work really well though.