I am wondering if it was possible to define an interface-range or interface-set or group or something covering all interfaces of an EX switch that has ether-switching family enabled ? Same way as appy-path would works for prefix lists.
Then I could use this group to apply rstp for : "set protocols rstp interface ETHER_SWITCHING_PORTS"
I think wildcard range is a better option that an interface-range.
With wilcard range you can apply the configurations to the desired ports in one command. The good thing is that if you need to use one of the ports later, you just delete the configuration from that port without affecting other configurations.
With interface-range you will need to remove the port from the range before using it.