A mic array won’t work if the environment does not fit. It does not make sense to test the performance with the bare breakout board when you plan to put it into a housing. And the housing needs proper acoustic design, otherwise it won’t work either.
This is for example the reason why EC will never not properly work for the Mark-I - the mic is a omni-directonal type and the speaker sits in the same “acoustic chamber” - blasting into the mic.
As written here I have built my Respeaker CoreV2 into the Mark-IIR prototype housing - and although the build is not finished yet the mic reception works far better than on my Mark-I.
Regarding open sourced software for EC: there is beamforming and EC support (via webtrc) available since Pulseaudio v9 (with some improvements in PA v12) where you can configure your mic-arrays geometry.