I believe part of what makes the VS Code experience is the extension store. Is this managed in some way with this distributed flavor ?
I’m using VSCodium daily and most extensions work, with the notable exception of official MS-published extensions, which mostly require VSCode.
This might help.
For me, VSCode keeps screwing up file encodings in a legacy project i maintain. I tell it not to autoguess the encoding and define a specific encoding to use. VSCode ignores that and keeps autoguessing.
VSCodium honors the settings (and is a wee bit more private and open-source).