MS-DOSisms like the BIOS int 10h mode switch you mentioned in another comment are included, but so are things like (xterm) 256 color codes, TrueColor, and alternate screen switching, which IIRC were not a thing in ANSI.SYS. (The color thing I'm very sure because VGA text modes only supported 16 colors, the alternate screen mode is only a guess, it's very popular in unixy terminal emulators, but seems mostly useless for DOS.)