The Celtic Camino - Any Advice?

You don't need to run it by anyone. If you have a few stamps and a Celtic cert showing 27km or more, you'll be fine walking from A Coruña to Santiago to get a compostela. Bring the cert with you.. (it's officially 73km from A Coruña). If you walk from Ferrol you won't need a Celtic cert as it's over 100km. Don't sweat it. Camino Ingles is very popular now and well marked.

Your certificate might get crushed. Take a scan on your phone, or a photocopy. As Flog says, it is not needed from Ferrol.

I had no problem in June 2022 with getting my Compostela at the pilgrims office. In Ireland, I walked St. Kevins Way, there is no certificate for this. The Irish Camino Society sent me a Celtic Camino certificate, when I sent them a copy of my 2 Wicklow stamps. Off I went to Galacia a week later, and had a lovely camino from A Coruna to Santiago
It was a nightmare getting out of A Coruna, with few markers, and all difficult to locate. This is mentioned in John Brierlys' 2022 guidebook, but of course I thought it could'nt be that difficult. Once out of the city, it seemed to be marked every 50m!
On my second day I met a group who had taken a taxi to the outskirts, having read John Brierlys' comments about the lack of signage