A parallel hijackable thread could run. It was have to be clear from the start what it was. Probably in IMHO or the Pit. It would have say “parallel hijackable thread”* right in the Title or I could add a new tag if this got popular.
The OP should linkback to the main thread.
We really don’t want omnibus threads in P&E or GD also. Apparently these caused problems in the past and I recall at least one in recent years we allowed for a while and it got ugly. Overall we usually moderate or close these.
* Or something else very obvious. I’m no wordsmith.