Update! One week old today. I think bi-weekly should work for updates.
Progression;
Egg set 6-6-18, Hatched 6-27-18.
Weight on 6-27-18: 33 grams.
Weight on 6-30-18: 38 grams.
Weight on 7-4-18: 54 grams. Growing well!
The tag is indeed growing larger, and remains attached to the skin, easily manipulated at the point of connection, but firm and sensitive to pressure on the body of the tag itself. I am starting to think that it will continue to grow like beak and toenail material, which is what it resembles. I've tentatively dubbed the chick 'It'.
Photo of tag;
View attachment 1455597
Photo of chick overall;
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The chicks are all doing marvelously and growing fast, loving their freedom out in the integration pen.
It looks like a toenail!

Beautiful chick though. I hope it continues to be a non-issue. Have you considered how you would remove it, if it ever seems to be a problem?