Presumably most of those are the wills of people who lived in those few Flintshire parishes or townships that lay within the jurisdiction of the Bishop of Chester. But in addition some people from North Wales certainly moved to Chester to set up in business -- as was the case with Harri ap Ffoulke Salesbury, one of the cadet-line grandsons of the Piers Salesbury of Bachymbyd who married the heiress of Rûg: for MS pedigree refs., see Bartrum's WG2, page Salesbury 9, and the note to that page shown in Additions & Corrections vol I (Harri/Henry's son Ffoulke was landlord of the Talbot Inn at Chester, and became one of the city's aldermen: NLW Wynnstay MS 144 p724.)
Many people would also have come to Chester for shorter term business or social/pleasure purposes, including marriage (c.f. my Reply 17); but it seems unlikely that their period of residence would have been sufficient to justify the diocese of Chester gaining jurisdiction over their wills.
Some of the people in this category who possessed larger rent-rolls had town houses there, as also happened in the cases of Oswestry (a bit) and Shrewsbury (more so). If their own ancestral estate was remote and wild, such people could develop home-sickness in its alternative (i.e. opposite) meaning and end up becoming almost full time city-dwellers. But the normal result of such multi-jurisdictional property ownership would be to make a PCC grant necessary.
In the earlier 17th c., when the Court of the Council in the Marches of Wales (based at Ludlow Castle) was still very active, there could be legal reasons for leaving one's home parish and moving to a more congenial base such as Chester, where the court's writ no longer ran as once it had. Many years ago I came across a rather venomous land dispute in western Denbighshire temp. Charles I in which the complainant had been successful at Ludlow but the defendant (his mother as it happened) was defying the court's decrees. He lost patience, had the land sequestrated by the sheriff's men and had a warrant issued for his ma's arrest. But she outwitted him, as he later bleated in a Chancery bill, because
... she hath withdrawne herself and her habitac'on ... into the cittie of Chester, where shee now liveth
No idea whether she stayed on and died there -- never found a Chester will (or any other sort) for her, unfortunately. But she was certainly a fighter, and no doubt others occasionally moved out of the wilds of Wales to Chester for similar reasons, and unlike her did leave evidence of the fact in the probate records.
Rol