I am intrigued by this Nashivlle tuning and I must have missed the thread(s) where it was mentioned. Am I understanding it correctly in thinking that it is dropped D tuning but with the lower 4 strings tuned an octave higher than usual?

Jed, I am not an expert on these matters and certainly not a luthier but it seems to me that you have a couple of strings that are tensioned normally. Why not use those as a reference point and experiment with custom gauges for the others until you find a balanced setup ie use even lighter guage strings for the ones you are having to tune high?

Jon