I am also of the opinion it was during this part of the 18th dynasty. 12th dynasty is much too early. Exodus was at least 400 years after Abraham who was around 12th dynasty. There were dark skinned, curly haired people found east of the Black Sea who may have been Egyptians posted there by Sesosteris II or someone in that era.
The RC dating of Ramses II, 19th dynasty (using the contents of his canopic jars) turned out to be over 700 years younger than the conventional pseudochronology claims, but that is the date that Velikovsky gave for him. An 18th Dynasty Exodus is completely hopeless.