It seems the prevailing theories for the second s of Douglass are
1) Clerical (3rd party) errors
2) Illiteracy errors (self errors)
3) Disambiguation between clans (Black and Red)
4) Something else.
So far, my research originated and…"
As a little boy my GF insisted that I always use two s'es in my name. My GF was born in 1898 and lived to 93. My grand-uncle (GU) was b 1896 and lived to 99! So I got to spend a lot of time with them hearing, recording,…"
The more information you can give about the people you mention, the more chance there is of someone else connecting with your family.
Dates and places of births, deaths and marriages all help to place families.
Professions also help.
'My great-grandmother mother was a Douglas from Montrose' does not give many clues to follow up! But a bit of flesh on the bones makes further research possible. But if we are told who she married, what his profession was and where the children were baptised, then we can get to work.
Maybe it is time to update the information in your profile?