The presentations are a very important part of the brainstorming as they are sharing the outcomes of the idea with the stakeholders who can decide whether the ideas should be implemented or not.
To keep presentations consistent, use a template and ensure the following is covered:
In order to get through all the presentations in 1 day, allocate a strict schedule.
E.g.:
If the team has a demo to share, get them to pre-record it and embed it into the PowerPoint. This will save time and ensure the demo goes smoothly.
To help presentations run smoother, it's a good idea to set up a presentation run sheet and then share it with the attendees on the day.
This could be in a GitHub Discussion, Microsoft Loop, or Word document.