Have Purism explained their processor choice anywhere? It would have been nice to have used the i.MX 8 QuadMax - it would have given a little more hope for the phone lasting.

I'd guess that power consumption characteristics of those two i.MX8 variants are different enough to explain that choice.

Well, the mainstream phones have much more powerful processors than Cortex-A53, they just power manage them well…

I wouldn't expect a SoC that's not even targeted for mobiles to "power manage them well". Mainstream phones are completely irrelevant there.

Oh, I didn't know. Nevertheless a Pinebook with Vivante graphics at up to $250 would be pretty nice. If there is a better SoC with as good mainline support, all the better.