I recently ran into an issue where I was trying to create a cursed  bag of holding. I used a basic bag of holding as the template as it seemed to be the quickest way to create the item. However once it was created I noticed I was unable to place items in it on the character sheet like a basic bag of holding. It did not create a storage location on the character sheet to put items into it. Is it possible to have a check box or drop down menu option when creating a magic item to create a storage location in the inventory much like the basic bag of holding does automatically when it is added to the character sheet. I am aware this is a small issue that can worked around but No offense I don't pay for DnD beyond for work arounds. Perhaps i missed an option but I couldn't find a way to make the storage location pop up on the character sheet or give the new item a capacity like the bag of holding does. Thanks in advance. 

I have also noticed this, seems like the "Capacity Weight" attribute that can be overriden on the existing Bag of Holding is not exposed in the Item Basic Information or Additional Information and is not related to the Carry Capaicty Modifiers. The annoying thing is that you can't even create an item using Bag of Holding as a template and keep its Container status.

The feature is not supported. 

You can just add an equivalent existing item and customise it. 

I'm having an issue creating a new container itself that will only contain paper, ink, and pins. It isn't actually letting me use it as a container though. Any ideas on how to modify/make this work? I'm trying to create the item instead of a custom item so it can be used by multiple people instead of having to make a custom item every time I want to do this.

You can't make homebrew containers, so that is probably why.