This is now available in the latest beta (3.1.1.1) via “Preferences - Connection Types - Terminal - Plugin Settings - Warn before pasting when not at shell prompt”.
HI, I found this same problem. Just to confirm, this is to interrupt before pasting with a newline? The preference you listed doesn’t seem to be the same thing.
Either way, I’d love to have the old functionality back.
One suggestion, changing “Warn before pasting when not at shell prompt” to “Warm before pasting one or more lines with a newline” would be more helpful. To be honest, I have no idea what the current description would mean.
@Aaron: This was taken directly from iTerm2 but I admit it’s not quite obvious what the setting does. So we will change this to “Warn before pasting multiple lines when not at shell prompt” in the next release.