Hi @Craig Stanley, I'm pretty sure you may have seen the Miro resources for design sprint, they are really good! Just in case, I'll leave them here:

https://miro.com/blog/design-sprint-guide/

https://miro.com/templates/remote-design-sprint/

My good practices for large collaborative events in Miro would be:

• Have dedicated Miro learning sessions prior to the event start for participants to get used to working with Miro and the tools. It's a good time to iron out tech issues participants may have on their end so that they are not disruptive during the DS process itself. You may also uncover "Miro" leaders who can help other participants later in the main workshop.
• Always have dedicated personal and team areas for everyone in your board design. It helps with helping them visually focus on their tasks and not wander anywhere on the board or in their mind.
• Timebox everything! You'll be surprised by how much longer things take to setup during online events. Timebox each interaction moment so that you can move on efficiently. Also, I feel like people are a lot more engaged when using Miro. They are going to have lots of opinions and input to share, so again, timebox as much as you can.
• Design your online experience using Liberating Structures. If you're not familiar, these are really efficient, effective and inclusive ways of having meetings or brainstorming. More info: https://medium.com/@reimaginaire/what-are-liberating-structures-de6f6d14c2c8 

I hope that helps for a start!