Is your feature request related to a problem? Please describe.
If chest minecarts could deposit items without player input, they could be used to send items from the bottom of a mine to the surface, have them unloaded and then return, making building a railway for a mine more rewarding. Bringing items out of a mine often requires multiple round trips. I think it'd be more fun to build a railway and then occasionally send a cart up while I mine, then have it return and wait for me to load it with items again.
Describe the solution you'd like
Allow rails to be placed on baskets,
When a chest minecart drives over a non-full basket, the basket takes items from the minecart.
The player could place multiple baskets in a row with rails over them and they would gradually fill up as carts arrive. If a non-empty cart returned down into the mine, the player would know the baskets are full and it's time to go up and empty them.
If the basket instantly unloading the cart would be overpowered and it were to be gradual, maybe it'd be a good idea to add a way to distinguish between empty and non-empty carts (different signal strengths from the detector rail?) so that carts can be looped until either all baskets are full or the cart is empty, and only sent back down afterwards. This is not a deal-breaker though, because you can also calculate how much time it takes to unload a full cart and loop the cart for that long.
Describe alternatives you've considered
A similar behaviour can be achieved by storing the chest minecarts on the surface and crafting more to send up while in the mine. I think allowing the same cart to be reused by sending it back and forth is more fun, and chest minecarts interacting with baskets could have additional interesting uses for item transportation, but I totally understand if this is considered too "hopper-like" and/or overpowered.
Is your feature request related to a problem? Please describe.
If chest minecarts could deposit items without player input, they could be used to send items from the bottom of a mine to the surface, have them unloaded and then return, making building a railway for a mine more rewarding. Bringing items out of a mine often requires multiple round trips. I think it'd be more fun to build a railway and then occasionally send a cart up while I mine, then have it return and wait for me to load it with items again.
Describe the solution you'd like
The player could place multiple baskets in a row with rails over them and they would gradually fill up as carts arrive. If a non-empty cart returned down into the mine, the player would know the baskets are full and it's time to go up and empty them.
If the basket instantly unloading the cart would be overpowered and it were to be gradual, maybe it'd be a good idea to add a way to distinguish between empty and non-empty carts (different signal strengths from the detector rail?) so that carts can be looped until either all baskets are full or the cart is empty, and only sent back down afterwards. This is not a deal-breaker though, because you can also calculate how much time it takes to unload a full cart and loop the cart for that long.
Describe alternatives you've considered
A similar behaviour can be achieved by storing the chest minecarts on the surface and crafting more to send up while in the mine. I think allowing the same cart to be reused by sending it back and forth is more fun, and chest minecarts interacting with baskets could have additional interesting uses for item transportation, but I totally understand if this is considered too "hopper-like" and/or overpowered.