>> Equivalent but just as unsafe.

> To my understanding, the main difference between "curl directly to bash" and "curl to a temp file, then execute the temp file"...

It's not a temp file in the sense of a regular file. `<()` is also a pipe, hence equivalent. `curl` and `bash` run concurrently.

Running one after the other wouldn't be all that much of an improvement anyway if it's done automatically. One really should manually review the script before running it.