This is a new fundamental building block that would help make these types of scenarios possible. However, by the time end users get an implementation, it will l

This is a new fundamental building block that would help make these types of scenarios possible. However, by the time end users get an implementation, it will likely be more complicated than a single transaction for the reasons you mention and others. Also note, as exemplified by altcoins it is always possible to trade off decentralization or security for more features.