I think the mission crate from Venture tier 1 should not drop a 3x3 propeller, but a 1x1 propeller instead, since later on we get a mission with an airplane which uses a 3x3 propeller. This way, people are introduced to the smaller propeller, and get the chance to use it in their techs instead of just having it and never using it. Maybe even move the 3x3 propeller from tier 1 to tier 2. Below I included some airplane techs which use the 1x1 propellers to fly. One of them needs both the 1x1 propeller and a booster, while another one needs two 1x1 propellers only. All techs attached use small propellers for flying, in one way or another.