Matthew,
I see Marvin and Milo as more of a science kick starter rather more than literacy, since they are tagged as “DO try this at home” so I would use them as practical impetus. Are there particular ones that you would consider using or sharing with your class?
Other teachers have mentioned balloon rockets, but I like the homemade sunset: https://spark.iop.org/sites/default/files/media/documents/32%20-%20Marvin%20and%20Milo%20-%20Homemade%20Sunset%202019.pdf
Do note, that sometimes the language can be a bit complex, as in Eerie Blue Water (https://spark.iop.org/sites/default/files/media/documents/62%20-%20Marvin%20and%20Milo%20-%20Eerie%20Blue%20Water%202019.pdf) 