The EuroAristo dividing line is at 1500 - nobody said anything about extending this to 1700.
It's a tricky period because hereditary names were coming into use and English spelling conventions were in common use. So the Quaker Meeting books tend to say Owen, Hugh, Rees rather than Owain, Huw, Rhys.
Then it looks uncomfortable to write Jane ferch John with the Welsh spelling of ferch between two names spelt the English way.