A length distinction is said to exist for all consonants except /w j/. This apparently *does* apply to the rhotics. (But see pulu1242-2 -- in Elbert's grammar, the phoneme given here as a tap is described as sounding like the "American r", i.e. an approximant)
ɛ / "after velarised bilabials, /a/ is raised and fronted"
ɛː / "after velarised bilabials, /a/ is raised and fronted" (presumably this applies to its long equivalent?)