The other issue you will have with Meraki, you can't manage them with SNMPv3 which is an absolute must have for doing so over the public Internet as Spectrum won't allow a forward slash / character in the user name which is, sadly, how Cisco auto-generate them! I have a request out to CA to allow / in SNMPv3 usernames and it will apparently be delivered in a patch to 10.2.2 at some point.
What would make more sense, instead of doing it that way, is an integration like Ciscoworks etc. where you put in a URL and some credentials and then Spectrum creates a sort of proxy-model from what it gleans from Meraki.
To overcome some of our issues with Meraki, at least supporting our internal kit, is to have local SNMP strings defined too. If you have customer-hosted SpectroSERVERs with a Meraki element to their network as well, you could look at doing it that way, at least until proper support for an already 2 year old technology is eventually catered for in either Spectrum or as a UIM probe.