@tubetime AFAIK NSC only called the original PMOS version PACE, and always referred to the NMOS version by the INS8900 part number.
Oddly enough, the NMOS version had the same timing specifications, rather than being faster than PMOS.
Years ago I discovered that the commonly found scans of PACE fig-forth were missing a page, and also had another serious bug. My corrections are on Bitsavers. The author of PACE fig-forth said that as far as he knew, no one else had ever used it.