I wanted to pass an array of strings to a module so I added them in themesettings.yml
AssetsToIgnoreInDocumentJson: [staticwebapp.config.json]
Then I tried to retrieve them:
var ignore = context.Settings.GetList<string>("AssetsToIgnoreInDocumentJson", []);
However, ignore == null. In context.Settings I can see that staticwebapp.config.json is paired to AssetsToIgnoreInDocumentJson:0. It's not wrong per se but it doesn't play nicely with IMetadataConversionExtensions.GetList<T>.