So if you want to get access to the Experimental branch of the game, all you need to do is on Steam, you right-click the game, you hit Properties, you go to the Betas tab, and then there's a drop-down list.

You can opt into Experimental, click it there, and that will reinstall the game for you.

And on the Epyx Games Launcher, it should just be its own game in the games list.

And that will install the game along with the installation you have of the regular game.

So good times, good times.