OK the results are pretty clear. Reminder: 2 x 200 ml samples. One sample got the zest of one small lime. The other got the juice from that lime.
These were clearly overdoses for 200 ml. You would want to workout some possible ration for your batch size, but I would guess that depending on the intensity of the lime fruit - 1 -2 limes to gallon would be a good starting point. If I recall, the lime yielded 25 mg of zest, and about a tablespoon of juice.
I filtered both samples through a coffee filter and sampled at room temperature.
The Juiced sample was awful. Clarity and color shifted with the additional acid from the juice. There was very low to no lime aromas - keeping the light orange blossom honey character. The flavors went very sharp and acidic, almost astringent. The acidic aftertaste was very long and pretty unpalatable. Maybe with just a much smaller fraction of the juice some complexity and acid balance could be preserved. Perhaps using the juice in the primary, but you would need to buffer that acid - or expect a very long maturation process.
The Zest sample was pungent and smelled of fresh zest turned to 11, overpowering the honey character. The clarity and color of the traditional mead remained unchanged, while the zest went from dark green to a grey (much like lemon zest in limoncello). The flavor added a low bitterness that might be considered astringent, but maybe perceived as a spice note. Otherwise, this was pretty close to the original orange blossom dry mead, with a little additional perceived sweetness, which maybe a trick of the retronasal. This was drinkable, but barely. Very intense lime smell is overwhelming.
Here are a couple of pictures: