I don't understand, they are on your client's website and want to access their home network?
What is the need for this?
Now if they want to access the client's network from their home network, why doesn't he just configure a VPN Client?
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.