I was always under the impression that k is 1000 and K is 1024 ... same as with g, G or m and M. Full ack on b and B, though. Maybe the engine is indeed only 512B in RAM utilization?
Edit: Turns out the official project's claim is indeed 4KB so the title is just bogus.
So, anyone who uses Windows has probably noticed at some point that "GB" "MB" and "KB" are the power-of-2 variants. Whenever I see one of those tech YouTubers say the formatted capacity of a 1 "TB" drive is 931 "GB" I just cringe. Most storage vendors use the power-of-10 definitions and Windows uses the power-of-2 definitions. 10^12 bytes / 2^30 = 931.32, so no, formatting your drive does not make 7% of the space just disappear.
Edit: Turns out the official project's claim is indeed 4KB so the title is just bogus.