Love your lists Aquinas!
If you don't have one already and do have access to an open area like a soccer field or rugby pitch, I recommend getting a Stomp Rocket. We bought one around that age and it is still a huge hit a year later. It is a light Styrofoam rocket that is launched when a child or adult jumps on a plastic container, forcing air through a tube to propel the rocket high in the air. We didn't get Stomp Rocket Jr, just the regular one for about ten dollars on Amazon. It would be a real challenge to cause injury with this, so the junior version is unnecessary. Anyhow my son loves to discuss thrust, trajectory, angles, etc and the rocket has been fantastic for his space loving pretend play
Thought I would pass it along because he has enjoyed it so much.