I guess my real question here is this- Simon Lynde IS on the list of Gateway ancestors- however Mary (? Lynde) is NOT listed as a documented Gateway ancestor. The LDS site and WikiTree have the following notes regarding the Beckwith History and subsequent publications:
This man's family has been the subject of multiple genealogical publications that contained serious errors. The Beckwiths (1891) by Paul Beckwith, and History of New London (1895) by Frances Caulkins are not reliable genealogies. Gen. Simeon M. Fox shows in detail the errors, with corrections, where books such as these and The Beckwith Genealogy and Beckwith Notes ascribe unfounded connections to noble lineages in England, and muddle the vital facts of New England families. There are many points of data conflict between these three publications and subsequent work by Fox, Dean Crawford Smith, and others.
The parents Thomas Beckwith and Anne Dynley previously attached to this profile were removed because evidence is lacking that they are related to this person.
The Beckwiths, by Paul Edmond Beckwith, identified Lyme, Connecticut, settler Mathew Beckwith as the son of Marmaduke Beckwith, a member of the English landed gentry, and his first wife, Anne Dynly. According to Paul Beckwith's account, Mathew was born in Pontefract, Yorkshire England, September 22, 1610, and emigrated to New England in 1635. [1] There is no known basis for this account of his origins. No records or other sources were cited as a basis for this identification, and analysis has found that Paul Beckwith's work was filled with fabrications.
According to The Great Migration Directory: Immigrants to New England, 1620–1640, the parents and origins of this person are not known.[2] Anderson cites Angell Ancestry 222-30 which discusses clues to his origin in detail.
Paul Beckwith identified Matthew Beckwith's wife as Elizabeth (“at his death he left a wife Elizabeth”[23]), but Fox and Smith both cited records that show the name of his wife and widow as Mary. Her maiden name is not recorded.[24][25] Matthew and Mary Beckwith were probably married by about 1643.[26]
https://www.wikitree.com/wiki/Beckwith-78