> Now on a '19 macbook air, because surely they've fixed it, yes?

Is there a 2019 MBA? I thought it was most recently updated in 2018. It certainly feels better than the older models, and even a smidge better than the 2018 MBP, which was updated earlier in the year. But there are still reports of issues with the 2018 MBA, including in the WSJ writeup IIRC.