This is a great analysis; unfortunately I have nothing to add, and don't have an answer. I see also, you've broken from the crowd of Deborah Baines being the daughter of Matthew Baines/Margaret Hatton. I've thought for awhile that this other line is more appropriate and your documentation of Gabriel's will definitely supports it.
I can provide Mary Ashton/Daniel Lee's marriage date in 1719 (vice Bef 1723):
Quaker CD -- Falls MM, Vol II, pg 975
1719, 7, 29. Mary, dt Thomas, Bucks Co, m Daniel Lee, Bucks Co, at MH in Bucks Co
Have you tried to connect this line back to Isaac Ashton in Ormskirk? I descend from Joseph Ashton, allegedly a brother of Thomas, without success to date. Feel free to write directly at email@example.com