we are mostly investing into automatic testing. Thats why we brought up lava.
Nowadays, we have our images go through boot testing and we run a couple of benchmarks. More automation is planned and we are happy to have you help grow that test base.
If you are interested in general or in a particular test area let me know.
Anyway, before we release at the end of the month we have those images undergo some more manual testing. This is not super extensive, but besides checking that the general UI experience works, we go through a list of hardware features and note down if enablement of those is fine or missing.
A slightly outdated list of the features we check is here:
https://wiki.linaro.org/Platform/DevPlatform/BoardSupportStatus/ComponentTestCases