Current Beta access program enables one to upgrade to macOS Mojave from a stable release, but I want to try out a fresh installation instead of upgrading with previous data, so that I can assess it better.
I've downloaded an application named "macOS Mojave Beta" from the App Store, and running it would presumably result in an upgrade. Now I wonder what to do next. Would creating a bootable installer and booting from it be a good idea, when I'm working with a Beta version?
Best Answer
There's some misconceptions here. Let's clear them up....
No, it gives you access to prerelease software that you can install on your device. They make no mention "enablement of upgrade." Granted, since Mojave hasn't been released, it will be a de facto "upgrade"
A better question would be, "Why wouldn't it be a good idea?"
A beta is, again, prerelease software and it will have bugs.
When you download the software, you are presumed to have read and be aware of this. There's nothing precluding you from attempting to install it via USB and it's encouraged. Should you find an issue, report it to Apple.
And....
It's important to note that Mojave and all beta software in general is being made publicly with the expectation that you leave feedback about issues/problems/bugs that you discover. Expecting the software to function without issue or as a fix for what plagues released software is an unrealistic expectation.
In other words, don't run this on a "production" machine and make lots of backups of your data.