Can One Message complete some Tasks?

Hello, is it possible to send one Message with List of “businessKey” or “correlationKeys” to continue execution all process instances from the Message List ?
User in Web Form select items, join they in one Package and send Message. This message must be received only by instances from the List in Message body. The main process looks:

I’ve made the additional process with multi-instance subprocess to solve the problem:

But I’m not sure this is optimal way. It will be better to get message and continue process execution in one place like this:

Is it possible ? Any idea ?