Enums and parameter properties can be enabled with the --experimental-transform-types CLI option.

Not being able to import TypeScript files without including the ts extension is definitely annoying. The rewriteRelativeImportExtensions tsconfig option added in TS 5.7 made it much more bearable though. When you enable that option not only does the TS compiler stop complaining when you specify the '.ts' extension in import statements (just like the allowImportingTsExtensions option has always allowed), but it also rewrites the paths if you compile the files, so that the build artifacts have the correct js extension: https://www.typescriptlang.org/docs/handbook/release-notes/t...