Hi, I am not sure about all the questions but for PG 11 support on Microsoft Windows Server 2019, In my opinion and based [1] and [2] we can say it was supported.
[1] https://github.com/postgres/pgweb/commit/276d28268de00de1c33de2b46db5f81888c60de9 [2] https://youtu.be/swkLKFNis5Y?t=15 - Umar Hayat
