The Orange Pi RV2 (Ky X1) uses the Imagination BXE-2-32.
The good news is that firmware is available for that variant. The bad news is that Mesa currently lists the BXE-2-32 as 'unsupported / not under active development' (unlike the BXS-4-64 in the TH1520, which is active). https://docs.mesa3d.org/drivers/powervr.html
So while the kernel driver (drm/imagination) is the right path, the RV2 is a steeper hill to climb: it needs the SoC kernel plumbing and likely some work in Mesa.
Ouch!!!
I will have to wait then. I may choose a supported variant then.