I worked at a company that would send these sort of messages over Slack, including a priority, and expect some kind of ACK back within a certain amount of time.

I worked at a company that would send these sort of messages over Slack, including a priority, and expect some kind of ACK back within a certain amount of time. It was the worst thing for productivity that I've experienced in a working environment, everyone hated it except for the CEO and CTO who implemented it. Receiving the SYN message already distracted the programmer who received it. If the sender had included the entire question or opening message all at once, then the receiver could decide if it was worth their time to answer at that moment. Instead the receiver of the message needed to break away from their thought process and devote time to determining the scope of the question. Do not recommend.