My gut is that for any ideation activity, individuals will have an initial set of ideas, and communicate this (whether spoken, or as jotted notes in the conferencing tool's chat). Those will have the earlier timestamps.
Then there are "spin-off" ideas, which you usually have more of in a face-to-face context, which will have the later timestamps.
I'd would have also liked to see if idea A inspired idea B, so a tree of ideas.
What I'm getting at: I'd like to check which of the "initial" or "spin-off" ideas were the "best" ideas. From experience, the initial ideas folks come up with usually spring from their prior experience, which means it's usually based on tried-and-trusted ideas which came before.
Also, I think it depends on the group: maturity, experience, etc. I generally hate big group discussions, and you inevitably have some in the group who dominate discussions. What I prefer is getting a meeting agenda ahead of time so I can come in prepared. Bonus if attendees can send their preliminary thoughts via email ahead of time. That will ensure that any verbal discussion is to the point, summarised, and leave room for any last-minute questions.
E.g. I would love more meetings to be like this one (involving Richard Feynman; he uses the phrase "great men", but I prefer "great people"):
https://juanuys.com/blog/2017/02/26/great-men-or-how-to-cond...