This thread might be old, but I've been told that if you turn off RSTP on the port, that the switch will no longer send BPDU frames out that port. Is that what you meant @jdsilva from your comment above about turning off STP? Or are you talking about a switch-wide, or network-wide option that I'm not aware of?
Ah ok so that is confirmed then. Changing RSTP will disable STP on port.
When I read RSTP, I think oh ok, its going to turn off RSTP but the slow STP will still be enabled. I guess that was my confusion.
Yeh that's a good point.
So right at the very top of that doc is says both STP and RSTP are supported. Further down in the explanations of the network-wide disable, and port level disable, it says it kills STP completely for the scope each setting is applicable too. I don't see in there any way to force a port into STP mode. I know in Cisco Catalyst RSTP implementations if an RSTP bridge detects an STP BPDU on a port is changes the mode of that port to STP for interoperability purposes (and thus slows down convergence of the entire RSTP domain), so perhaps it's the same with Meraki? Dunno, never had to connect an 802.1D bridge to an MS.
If you go into the port configuration on a switch there are options there that might interest you ..
Monitor -> Switch Ports -> Port X -> STP Guard