You can upload worlds, Avatars, but you cannot upload props.

Props would allow you to spawn in an item that others could pick up and play around with.

Props can be content gated: (Sexually suggestive, Adult Language, graphic violence, etc) and users underage cannot view these props (same system for avatars)

No props will be public use, so creators will still be able to sell them. Public props will annihilate the market for selling items, so players will still need to buy the prop to be able to use it. This can happen in-game through the use of credits, or on gumroad where they can upload it to their own inventory with their own customization.

Objects that I see being used as props include:

Vrclens, almost any Liindy object, controllable drones, swords and weapons, etc.

Uploaded objects will have their own FX menu's, parameters, and will be compatible with avatars 3.0 features like physbones, receivers, senders,

A possession system could use some hand proximity logic to tell which player is currently controlling the object, and a corresponding expressions menu can be added somewhere, maybe be outlined in a different color to show that it is to control the object you are in possession of.

I think that public props would be cool for easy sharing, but if a player was just able to save it to their inventory, it would completely get rid of the incentive to buy the asset. imagine if vrclens was public and saveable, anyone could save it and it would completely kill the incentive to buy the product. This is why I think public props shouldn't exist, because even if the prop was set to private by the creator, someone else could buy the same thing and set it to public.

Allowing other users to control things that can be loaded separately from the avatars allows for more creative expression and eliminates the need to apply a prop and expressions menu+parameters+FX to every single avatar you want to show it off with, or have to deal with stupid "Drop in-world" FX settings that are incredibly difficult to set up, and glitch out because they are still parented to your avatar, not the world.

World props just don't cut it for me, you have to find specific worlds for specific props and it would be nice to just have them available to whoever has purchased them.