Unable to use the SlackAdapter

[digitaldias]

My bot is a single-tenant bot, and is purposed to connect to Slack only.
Following the example, in Samples I cannot get this bot to reply in slack. If I swap around the endpoints, so that the "regular" bot replies, then it is working like a charm, but I can then not leverage the ability to reply in threads using thread_ts conversation property.

I guess my question has two facets:

1. Can I somehow respond in a new thread using my regular IBotFrameworkHttpAdapter ?
2. What about the SlackAdapter is broken? As soon as I try it, it complains that the request headers can't be validated and fails.

The issue I'm trying to solve is to have the bot reply in a new thread.