Skin Changers and Hidden Cheats — What's the Risk?

During a custom match last weekend, one of the guys was messing around with a skin changer. At first, it seemed harmless — just flashy weapons and skins nobody had. But someone joked about how some of those mods sneak in other stuff, not just cosmetics. It made me wonder, are there skin changers out there that actually give advantages without making it obvious? Especially in customs where nobody's really watching closely. Would be cool to hear if anyone looked into it deeper or spotted something weird during matches.