Hi all, many thanks for your comments and sorry that it caused a bit of a Barney! But all good and generally constructive food for thought
from all.
I'm happy to report that I nailed the shot this morning and sending to my client now so fingers crossed they feel the same.
In the end I decided that Eduardo's option of using Litchi with focus would work best. I flew single op and the focus point tracked perfectly
so i'm very happy, I think this "assisted" single op method is great for getting the trickier shots when it has to be spot on and you're not
relying totally on the accuracy of the GPS.
Thank you to the Ed and all the forum members for making this such an invaluable platform for advice and information.
Hope I can help out others one day too.
Cheers,
Jon