is it possible to change the inventory type of an entity

Hi! Basically, what is in the title. For context: I managed to get this working on Bedrock via an add-on that essentially created a duplicate of an Allay which then switched its inventory type to that of a Minecart with Chest, allowing it to be "opened". I am wondering if that is possible with the Datapack functions so I can play with that in Java? Or changing the container type of the mob in general. (On that note, I'd also like if you can add "tempted by held item" to a mob's behavior too. I've been really struggling to navigate datapack documentation in general compared to add-on's, but i wanna get into it.)