When you say ‘heavy,’ are you referring to the model or its textures?
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If it’s the model, then you’ll only have bad news; the maximum filesize for streaming .yft models in FiveM is approximately 16 MB. You may be able to get away with streaming a model that slightly exceeds this limit (say ~16.1 MB; I’ve done this myself), but usually you won’t have very much luck at all with streaming models over this size. If this is the case, then you’re essentially out of luck.
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If it’s the texture, then you have good news. You can ‘dissect’ the .ytd file of the add-on and divide it up into smaller parts that are more appropriately streamable for your FiveM server; the limit for .ytd files is also 16 MB, but these are easily editable or modifiable unlike .yft files themselves. Fortunately this eases the process of streaming the add-on. See this thread about the process itself.