I have a great idea! A new recipe could be a minecart+a personal safe becoming a personal storage minecart. It has double the capacity of a vanilla storage minecart, clicked to open like a storage minecart, and secure like a personal safe (optional), and most importantly, has the same momentum as an occupied minecart (vanilla minecarts have the same momentum as an empty minecarts even though chests weigh more than chickens). If it is impossible to make them secure, that is fine though they should still have the same momentum as an occupied minecart. If it is neither possible to secure them or give them realistic momentum, then tell me so I would know it would be useless.