Information about the new custom keyboard is here: https://flicktype.groups.io/g/beta/wiki/Custom-keyboard
Compared to regular App Store updates, beta builds are simply more frequent, sometimes less polished builds that once deemed stable enough are released to the App Store. You will need to keep the TestFlight app installed on your device in order to be receiving beta updates. You should also be familiar with reverting back to a previous build from the TestFlight app if you need to confirm whether an issue is new to a particular build, if it existed before, or what exact build number introduced the issue.
Please make sure to read carefully through the TestFlight changelog for each new build that you receive. You may post new topics for things that are not specific to a particular build, but we kindly ask that you send all build-specific feedback by replying to the topic of that build so that we can better manage it.
We are always looking forward to your feedback, good or bad! Smile.
Thank you for testing,
Kosta & Ashley