Tartan Sett Thread Counts - A Question for the Experts

[Morgan of Seattle]

This question occurred to me from Chas' post in my thread about a new tartan design. This seems like a new thread, though.

I've been using the Scotweb store's new online software to design a tartan in honor of my father. In the online information they provide, they state that a thread count of 216-288 is best for making kilts. Most setts are symmetrical, though. The pattern is repeated in reverse, each time. My design is asymmetrical, no reverse repeats.

Does this mean that the ideal thread count for kilt making would be doubled, or am I thinking about this incorrectly?

Any expert help will be greatly appreciated!

Cheers,
Philip