I have run a Developer Beta of the macOS on an external SSD for several years. It is attached to my main workflow iMac. I can boot into it and test things and look around. I don’t run Betas on any other Devices because I don’t have an extra iPhone or iPad. But, here is the deal. Should you install a Beta on any of your Devices? This article discusses installing Betas, how, where and when to install Betas and should you do it at all.