Gosh, there's a name from the past. I haven't see Evelyn since the mid-1980s.

Interesting article. A couple of observations:

Before 1750, there were many more patterns which were 'asymmetrical' or 'non-repeating'. By more I assume the author means than now but that is not the case. There have always been asymmetric tartans but based on surviving examples there are numerically, though perhaps not proportionally, more asymmetric designs now than in pre-1750.

Sett - there are many setts that are larger than 13.5 inches including a number of pre-1800 plaid setts. Of the contemporary setts Ogilvie/Drummond of Strathallan has the largest setting.

Similarly, the simplest is not Menzies but a two coloured check such as Rob Roy, Robin Hood etc.

Twill - most tartan is twill but some cheaper stuff, and some historical pieces are plain weave (1 over: 1 under).