Does anybody use the 'transfer line' feature?

[Nev3r]

If so, is there a reason you would prefer it over splitting the FOF targets and using different tags for each texture?

 

[Zwip-Zwap Zapony]

If one uses "Transfer Line" FOFs to make a square where the north and south sides have different textures than the west and east sides, while the whole FOF is transparent or translucent, would splitting the FOF from 1 square into 4 triangles result in the new inner sidedefs being visible from outside the FOF?

Or, with imagery:

If so, that'd be a reason to prefer using "Transfer Line" to set each side instead of slicing the FOF into multiple different-textured ones, to avoid visual "artifacts" inside the FOF.