Is your feature request related to a problem? Please describe. 🤔
So I am trying to load a model from Cobblemon mod, but they have only one entity and they use NBT data to load the models

Describe the solution you'd like 💭
I would appreciate, if I would have the ability to specify NBT data when trying to summon a NPC with a custom model.
Something like this /easy_npc render set entity ed3cec26-a657-4064-8436-8564fb722d6f "cobblemon:pokemon {"Species": "cobblemon:patrat"}"
"{"Species": "cobblemon:patrat"}" is the NBT data to load the model, in this case Patrat model

I would appreciate if this request would be added to version 1.20.1 forge

Thank you for the feedback. Supporting NBT data will only be a temporary solution since the upcoming 1.21.x update will no longer use NBT data, switching to a different data system instead.

To address this, I plan to add a feature that will automatically transfer the relevant data from the NPC to the custom model, ensuring compatibility with the new system. Additionally, I'll introduce "virtual" custom models for Cobblemon, which will allow for easier selection through the "model" screen.

This should help streamline the process and ensure long-term support for your use case.

I ran some tests, and it seems that simply adjusting the NBT data isn't working in this case. Custom models are client-side only, but it appears the mod is handling a lot of server-side processes as well.
This is why modifying the NBT data on the client alone isn't effective, unlike the /data ... command, which operates on the server side.

This indicates that proper integration is required, and it's not a minor fix.
I'll put this on hold for now and revisit it after the 5.x release.

Sounds good.