@Uberseehandel , It was more why boot it unstacked first, then let it upgrade the firmware, and then stack them together. I'd rather stack it, and boot it, and then let it upgrade itself whilst it is in a stack. But Meraki are quite clear in that they highlight boot it unstacked and don't configure in the dashboard. Then once upgraded stack it and configure it.
I suppose if you stacked two devices with incompatible FW, then they may not stack, and one or more may not upgrade.
@Nash I've rolled out 500+ Meraki devices pre-configring the lot in the dashboard, and got the installer to plug them in as documented, and only had issues when the wrong ports were selected. I found it more efficient. Those however were not stacked, so I have been backed into a corner.