I was able to upgrade to the current version microG Services Core version 0.2.12.203315 by manually. So now StopCovid France also works on a /e/ OS 9-Pie ROM.
SwissCovid Corona-Warning-App works with /e/ OS e-0.12-o and microG Services Core 0.2.12.203315
Stopp Corona Austria works with microG Services Core version 0.2.12.203315
(UK) NHS Covid-19 app works with microG Services Core version 0.2.12.203315.
Coronalert - Belgium App version 1.6.0.78 from 24.09.2020 works fine on my device configuration.
German RKI Corona Warn App works with microG Services Core version 0.2.12.203315.