Looks like GOG users can now participate in the Twitch events:
https://cloud.nomanssky.com/twitch

Is there a timeframe when we can expect to see these drops in--game?

As far as I can tell I'm correctly connected with twitch (it only says "connected" - can't tell what the connection is) and I've claimed drops for all 5 days. The campaign is over now but I'm not seeing the drops yet. Hence the question.

In my excperience the twitch drops appeared without delay. We need to go to the Anomaly and claim them at the Quicksilver Synthesis Companion Bot. There is a dedicated menu entry for Twitch drops.

When you say "without delay" did you check nearly immediately? What I have wondered is if or how the discovery server overloads for new releases or expeditions had an impact or delay.

Since I am already asking a question - are the Twitch rewards tied to a specific video or are they simply based upon total streaming time? For example, one reward required 3 hours of streaming time but did streaming once for 3 hours then also grant all of the other rewards for that day as some required 15 minutes or 30 minutes? I chose not to bother this time as I did not see that any of the Twitch rewards were something that I would use.

Thank You