I have had this same complaint, many times.
The problem is Meraki uses Apple's HLS protocol. I may have the exact specifics wrong, but my recollection is that start it starts sending the video in 2s bursts, and the player can't start playing until it has three 2s bursts. As a result, there is a 6s barrier straight away that can't be improved upon. Then on top of this add network and processing delay.
I have gotten it down to a 7s lag, but have not managed to get it any better than that.
Now forgetting Meraki for the moment; I have heard talk of Apple trying to make a version of HLS with a faster start time. But even if this is done you will have to wait for both Meraki and your favourite browser vendor to update both of their ends before you can take advantage of it.
I wish Meraki would support something like RTSP, but I guess there is some complication with doing this.