Can I stop an emoji reaction once it's started?
At this time, the only way to stop an in-progress emoji reaction is to close the app completely. You can do this by clicking the three dot button in the top right corner and selecting "close." However, please note that every time you open up the Epic Reactions app, it counts as one meeting used towards your monthly limit.
You can also drag the "Display Time" slider bar all the way to the left, but this doesn't stop the reaction immediately.