Chat Waterfall

Split the group in half. For example by first letter of their last name: A-M is Group 1, N-Z is Group 2.  

Prompt Group 1 to type into the chat box without yet hitting "enter" in response to the prompt. (e.g. what's one idea you have as a potential solution to this challenge?).

Once you've given them time to type, have them hit enter all at the same time ("on the count of 3."). This creates the waterfall effect in chat where everyone's responses come in at the same time. 

Everyone then has time to read everything that Group 1 wrote, before the facilitator instructs them to write responses (in the instance of ideas, these responses can be "yes and-ing" things that Group 1 wrote), and then has them hit "enter" at the same time.  Everyone then has time to read everything Group 2 wrote.  

Switch roles.

It's nice to play music in the background for this.  With a large group, this can take some time, as a lot of content is surfaced.