To clarify about the fake nitro plugin of Vencord/Vesktop:
It’s not Nitro, it just enables some features you get with nitro, mainly better streaming quality and being able to “send” emojis from any server (this is all it does, cant use any emoji reacts nor send bigger files or server boost).
Also
About the emojis, the custom/other server emojis are sent as image links which discord will render but it is not a native discord emoji and will format differently when used inline.
It also does nothing for custom emoji reacts.
About streaming, Discord uses webrtc, that usually means P2P streaming which in turn means that the streaming client can send whatever they want (as long as the receiving clients understand it) and discord servers can’t say no. It’s not server authoritative communication, discord without nitro just hides the UI options, vencord gives them back.