Both in a MacPro (mid-2010) with subsequently built-in USB 3 card and on a MacBookPro (Early 2013) no BluRays let burn. Device is detected, DVDs also burned, but at BluRays (Verbatim branded product, not a cheap scrap) it makes the opponent. Telephone support from LG also not really helpful: Macs would not just support what nonsense the part goes back again.
Addendum: I've the Archgon External Blu-Ray burner USB 3.0 Aluminum Silver for PC and Mac (is a Matshita UJ 272 installed) runs connected risen. Shame on LG!