Channels update

1. It was a big change, but overall I think sentiment is net positive across a good chunk of the network

2. The most common frustrations:
a. losing access to a favorite channel, esp. if you had a streak in it
b. seeing your reply "below the fold"
c. older casts in channels disappearing from personal profiles
d. many channels not having clear instructions for joining

So what we're doing this week

3. Continue to talk to users (mostly me) and pay attention to feedback

4. We're considering some tweaks to how above / below the fold works for non-members, esp. if the original caster is following someone. We won't make any sudden changes here, fwiw

5. Strongly considering adding back older casts in channels to profiles (with a label on the cast). The data is untouched at the protocol level, just hidden on Warpcast right now.

6. Continue to get feedback from channel owners / mods / users / developers on making request to join a channel a primitive similar to invites. Again, no sudden changes.