Chameleon Skin can also be a freebie: it’s a passive means that grants gain on Stealth Checks. No tactical implication; it just can make the yuan-ti superior at what it previously does.
If ruled which the trait lasts https://crithitceramics.com/the-importance-of-setting-in-a-campaign-a-guide-for-yuan-ti-pureblood-monks/