Hi,
I think what you are looking for is published in these articles: https://documentation.meraki.com/MR/Firewall_and_Traffic_Shaping/Global_Bandwidth_Limit_Consideratio...
I think the best practice depends on your environment.
If you setup an SSID bandwith limit of 5Mb/s MR access points in this network will refuse to pass more than a total of 5Mb/s for all clients associated to this SSID. Clients could be further limited by configuring a per-client bandwidth limit, but even a whitelisted client on this SSID would be capped at an absolute maximum of 5Mb/s.
If you have +-350 client devices this would be a good idea but if you have 10 devices you might as well give them some more bandwith.
Cheers,
Ben