IRL approach controllers often give altitude and speed commands, or heading and speed commands together. Sometimes they give all three at once. On approach if I want to do this, I have to give the altitude and or heading, and wait for them to read back the vector before I issue the speed command. This can also happen vice versa. Sometimes it is imperative that the pilot follows all three commands quickly, such as during an ILS clearance while trying to change an aircraft’s speed to maintain separation from the one in front of him. Though this feature might not often be used, I think being able to give all three instructions in one command could reduce the workload on approach, departure, and center controllers.
I think this has been requested but maybe not here I fully support this.
I support this as well, it reduces the amount of radio transmissions required.