ROM Hack Question Pokemon SwSh Model Swapping

[HydrosPlays]

I am trying to swap a Gigantamax Pokemon with another. I am trying to view Melmetal's GMax model in the Pokedex screen but I tried swapping the gfpaks of a GMax with Melmetal's GMax and it just crashes the game, so not sure if I am missing something? If anyone could let me know how to basically swap a mon for another so I can get the Pokedex screen, I am trying to create high quality GIF images of each mon and Melmetal's GMAX is the only one left.


Any help much apprecaited!

 

[Unity150_magickavoxel]

I am pretty sure model swapping or editing is not possible at this moment in public I think.