As far as I can tell you’ll be fine, provided a hub with enough power supplies the external drive and not the MBA. Once the power issue was addressed I was even able to use the basic disk creation facilities in Finder - as a matter of fact, those then showed up automatically.
That said, I have no idea if Bluray demands more power as my needs never exceeded the 4.7GB space of a single sided DVD, let alone its DL cousin. The ASUS Zendrive V1M I use is M-DISC capable and those demand a bit more oompf as well due to the different materials used (hence the reduced writing speed), but I have no power measurements for it. They’re a tad on the pricey side to experiment with as they’re marketed as capable of outlasting the heat death of the Universe 
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