I agree on the concept that LOF is the better option, for less stretch and stability ...
... plus eliminating seams.
However ... as an interesting segue,
... the only time I have had wavy borders was for my FWS quilt, when I was "smart" using LOF!!
And what a bear (no pun intended
BearIsGray!
)they were to get flattened out.
I finally got them there, but it was not a good experience at all.
Yes, now, I only use WOF.
Of course, that will change someday when I choose a border print running LOF!