Jinja, what I have tried to express in my comments are the form and purpose of the Coronation Rite. The precedents that you cite were specific to their circumstances: James I was King of Scotland many years before he became King of England, hence his coronation at Westminster in 1603. Charles II succeeded to the Throne in 1649 when it wasn't possible to have his coronation at Westminster, which took place in 1661, after the Restoration.

The situation today is very different where we have a free association of independent nations that comprise the Commonwealth, some of which also recognise The Queen as their Head of State. The Coronation is fundamentally a Christian Rite of consecration and investiture: a repeat would be superfluous and potentially blasphemous. An independent Scotland regarding the Sovereign as Head of State would not require a separate coronation any more than New Zealand; with a different Head of State but remaining within the Commonwealth, any more than India.

This is why I have also stressed the importance and usefulness of localised Thanksgivings (and secular events that always accompany these occasions). I see the pragmatic solution as a Thanksgiving in St Giles' Cathedral, Edinburgh, with the Honours of Scotland displayed on a table near the Throne.