While the second beta version of Android Q officially only launched on Google's Pixel smartphones, Alphabet's subsidiary also delivered a way to get the very latest build of its operating system up and running on third-party devices as well.
It did so by releasing GSIs, or generic system images of Android Q Beta 2. Those can be downloaded right now and should be compatible with virtually every Android device released over the course of the last year and a half or so. The only true requirement for running any particular Android Q Beta 2 GSI is having a device that's already powered by software taking advantage of Project Treble, Google's software compatibility initiative meant to address the heavily fragmented nature of the Android ecosystem.
Originally introduced with Android 7.0 Nougat in 2017, Project Treble became mandatory for all manufacturers shipping devices with Android 8.0 Oreo and later versions of the mobile operating system. You can think of it as a feature but what it essentially constitutes is a global initiative that reworks some of the fundamentals of Android and the manner wherein it's both implemented and updated outside of Google's workshop.
Project Treble separates the core components of Android from nearly every vendor-specific implementation of the OS, placing all custom additions to the firmware into a separate bin so to speak, and leaving the main framework unaffected. In practice, it significantly cuts down on the development time required for updates that deliver relatively incremental changes to the core parts of the OS but are still highly desired, which is precisely what's the case with security patches.
While the vast majority of Android devices in use today still doesn't have access to Project Treble (Google estimates over 90-percent of those in the wild are stuck on Nougat or an older firmware build), the effort already improved the overall state of mobile security in the top end of the smartphone price bracket, particularly so among Galaxy-branded devices as Samsung managed to leverage the change to the point of immensely improving the consistency whereat it pushes out stable security patches to its customers.
Project Treble is also the reason why many more third-party smartphone makers will be partaking in the Android Q beta than what's been the case with Google's previous OS testing programs. While those partners are still working on getting their custom implementations up and running, they're likely to be ready for a global launch by early summer and Google itself should be releasing device-specific versions of stock Android Q by this time next month when those are expected to be announced at this year's edition of the company's annual I/O developer conference.
In the meantime, anyone interested in checking out Android Q for themselves can do so by manually installing a compatible GSI on a Project Treble smartphone or tablet. This is still an unstable firmware build so trying to rely on it as a daily driver is not recommended regardless of how stable it might seem initially. It also comes with no promise of support and any bugs or other problems encountered therein won't be accepted by Google's main Android Issue Tracker.