brunopalermo I think the main benefit of this method is that you can define different collision polygons for different frames/animations on the character, for better interaction with other objects. (Say, extended arm with a sword in "Attack" animation will damage enemies etc.)
If you have Platform behavior on the same sprite, then constantly changing collision polygons can mess with Platform movements. For example, that extended arm with the sword will push the character away from walls. Or character can collide with the floor on some frames and "jump" for a few pixels, or lose connection with the floor and switch to "falling" state for a brief moment.
If you have events like "If Platform is falling, Set animation to Falling", the character will switch from one animation to another very quickly.
You probably know all this already, in this case I was explaining it to ssaamonn
— Simply create a rectangular sprite the same size as your character, make it invisible.
Add Pin behavior to your character, on start of layout pin it to that sprite.
Remove Platform behavior from your character and add it to that invisible sprite.