I will look closer into private contact discovery across messengers, sorry for rushing over that point. I did try to respond to the sopoena comment in that tha

I will look closer into private contact discovery across messengers, sorry for rushing over that point. I did try to respond to the sopoena comment in that that is only of limited value. A blackhat will proably have an easier time getting to servers than a lawyer with Signals setup, and I do credit them with providing a substantially better assurances than say Whatsapp... but still not good enough for my particular threat profile. Personally I don't like using permanant non anonymous identifiers like phone numbers so I would not use the feature as they have implemented it, but that doesn't mean it does not have some value for some use cases worh exploring. That is at least something that can be looked at objectivly in the scope of the spreadsheet.