The [Experimental] is only available from the various subscriptions-based site such as
https://subscribestar.adult/momoirosoft
https://www.patreon.com/momoirosoftware
The [Experimental] version is supposed to turn into [Public] 1 month after it's being release, but as in every cases since this project was launched here, there's unplanned problem that pushes back and deadline are rarely met.
The latest news (you can read about it on both site above) is basically telling you:
"We don't know what we're doing and we're learning. Thanks for sending us money while we constantly change our project on whims because some stuff sound cooler than what we made up to now so we constantly scratch our work, never reaching anything concrete!"