hi, just checked this article,
yes, this is the easiest linear enlargement
apply LeftSplit or RightSplit of any 2-parts THK to get any 4-parts THK,
left for 4n-1 , right for 4n+1
begin with simple THK as 2-parts or 1-bight, we can get quite a lot THK by only apply LeftSplit or RightSplit linear enlargement.
linear enlargement is especially useful for small THK.
for 55 THKs below 10, only 3 can not be made like this: 75 85 97, and their mirror.