Hey all,
Starting yesterday (September 12th), any time you open a composer window, you’ll see a toggle that will allow you to more easily turn the beta composer on or off, rather than having to navigate to the Beta Features page in your Settings. The first time you turn on the toggle, you’ll receive a popup explaining the features of the beta composer, with links to documentation and an educational video.
If you already have the experimental feature on, this toggle will automatically be turned on in your editor. We hope that this UI makes it easier for you to test out the beta composer! 
In the meantime, we also wanted to respond to the feedback you’ve submitted in this thread. Since this is a beta, we do expect that you may encounter bugs. Please report any bugs you find through the “Submit bug” link since that will help us most efficiently address them.
For all the bugs that have been reported, we will be resolving them before we officially release the composer post-beta. In addition, we’ll include an update at the top of this forum post once each bug is resolved. For any other feedback, we encourage you to use the “Submit feedback” button on the experimental feature, so your ideas can all be collected in an organized manner, allowing us to easily consider them for follow-up work.