only ref I've seen to Manx born is to children of Mark(e) Keed(Kead/Kidd) who married Elizth Wood Malew 18120817 - he is buried (as Kidd) Malew 18241226 (will as as Kidd)- Elizth then married Richard Costain - she is in Douglas st Castletown as sailor's wife in 1841 with two ch by 1st marr (as Kead)
There are a couple of earlier 'Kidd' entries in Braddan/Douglas as Isabel Kid(d) m Danl Cowin with ch bapt in Douglas (+ also a methodist preacher George Kidd was based on Island in mid 19th C)- I think this is a Liverpool name for some of period.
No link to Keig (phonetics would also be against it) that I can see