The main limitations of the multitasking command window were that it couldn't be used to drop into a language like the inbuilt BASIC interpreter and then change screen modes in BASIC code, or draw graphics using the BASIC plotting keywords, and so on. The command-line UI foreground and background colours were configured in the host app (typically Edit) rather than being changeable dynamically from within the command-line environment. There may be other limitations that I am not aware of, but for text-based interaction with typical command-line tools or BASIC in text-only mode, it's fine.