According to display analyst Dylan Raga, some Android devices can already change refresh rates within the same display mode, but their OEMs had to implement support for this at the kernel level. The problem with this approach is that each OEM would need to write its own logic for when to ramp down the refresh rate. This is challenging not only because of Android’s Generic Kernel Image requirements but also because the kernel has less insight than the OS about exactly what content is showing.

That’s why Android 15 implementing proper support for VRR/ARR at the HAL level is important, as it provides a unified way to ramp down the refresh rate using information and hints that are more readily available to the OS.