I'm not a technical coder, i'm a business coder, with barely passable knowledge of IPs, hex and binary, bitwise operators, etc. I googled my way into understanding and had fun with this one. Very interesting, concise, well packaged, enjoyable. Thank you for the great kata. Not sure why it's still beta.

how can we determine the outlier type from the first 3 elements? can't it be all even or all odd until lets say the 1000th element?

This is a technical Kata, it requieres some knowledge of network addresses to understand the description.
Although all terms are explained in the description, it's quite brief and may not be enough for some users.

I suggest we link explanations for MAC and IPv6 addresses. If someone is struggeling with the technical nature of
the Kata, they have a good starting point :)

If all hexadecimal characters in the output have to be lowercased,
it should be stated wether we can expect a lowercased input as well :)

fixed

fixed

Approved

Missing useful assertion messages

then invert the U/L bit, which is the bit 1 of the highest byte of the MAC address.

This part is not clear, should be flip the 7th bit of the first 8bit as refered in the video

Missing module and solution imports (sample and random tests)

Fixed.

Ruby translation kumited -- please check and approve

Well, I tried to move bits from preload to test case and it works too. I am wondering if there is a way to call author's solution in the test case so that there would be no need to duplicate the implentation.