Again a good, if slightly long article as it includes the non Meraki VPN peer information that could be separated? A couple of tweaks suggested below:
The net result is an automatic mesh site-to-site VPN solution that is configured with a single click. - If you had one hub with one WAN connection and many spokes with one connection each then there is no mesh, perhaps the word mesh shouldn't be in this particular sentence?
This option is only available if the MX-Z device is configured as a Hub. - it only applies to a hub that is not in VPN concentrator mode, this should be made clear.