I am happy to report we have the first YDNA testee from the Dykeman, Diteman, Dyckman, etc clan. FTDNA has a new Diteman & variants DNA project with its first member being tested - a Diteman who may connect to the UEL Dykemans of New Brunswick Canada and NY. He thinks he is descended from Garret's son Moses.
Now if only some other of the line will test we can see what Jan and descendants YDNA looks like and connect the variant families.
My grandmother was a Dykeman of the UEL Gilbert Hatfield Dykeman. They always pronounced the name as Diteman.