You could make it so the system tries to establish an IKEv2 connection and then drops back to IKEv1. ASA's can do this. This would involve no GUI changes, but it would break some things so support would have to be able to change it.
They could provide an extra "toggle" so it can be set per-non Meraki VPN.
One thing I do know - they will be wanting to make it Meraki simple.