@chad, @epriestley - just want to verify this is the behavior you guys want? (the back button / page history should have no interaction with the durable chat column basically)

I want to verify because my guess is this is complicated to get right. :D

I'd maybe start with this:

• When a thread is selected in the column, save a server-side preference (like we do for column open/closed).
• If the preference is set and points at a valid thread, default to that thread when rendering the column. Logic might look like:
  • Pull the defaults.
  • If it's there, great.
  • If not, do another query to look for it (and stick it on the front if we hit it, I guess?)

That's probably a little bit of work because of the query stuff and will be a little odd (ordering may feel a touch jumpy?) but I think it should mostly align with expectations and get rid of most of the funk here.

It probably won't make the preview / typing a message case seamless, but I think that's less important. And maybe it actually does?

I do expect this general class of behavioral stickiness overall, but I'm not sure how valuable sinking the effort in to get all the fine-tuning and details of draft stuff working ahead of other refinements (like showing threads with mentions or new messages) is.