Okay, I wrote a script to connect to a pub and by observing it's behaviour, check what version of the replication protocol.

• really old: it just calls createHistoryStream loads
• legacy: it calls history stream once, and then more times if you call a create history stream.
• ebt: supports ebt, should fall back to createHistoryStream if client calls createHistoryStream. Backwards compatible with legacy.
• ebt, legacy=false: doesn't do createHistoryStream no matter what. not compatible with legacy.

I have updated sbot to include ssb-ebt and ssb-ooo by default. I'm gonna have a cup of tea and see if I can think of anything I still need to do before publishing this.