Mixing tartans - yes or no?

[Morris at Heathfield]

my kilt is Campbell of Argyll - which to clan purists is somewhat beyond the pale.

I seem to recall that, on the CCSNA website, it said something about how, if you already had a kilt in the Campbell of Argyll tartan, not to worry about it, but I can no longer seem to find it. Perhaps they figure the message has gotten out by now. (Apparently not, however. Fraser & Kirkbright and the Frugal Corner, for example, only offer the Campbell of Argyll, although they offer the Black Watch in modern colors as well.)