I believe that shulker a should be accessed easily, For Example: when you have nowhere to place it but you want to put something in or take something out, you should be able to right click it in some way and it will open while in your inventory.
A similar thing already exists.
You can use /sh while holding a shulker and it will open the shulker
You can also right click while sneaking to open a shulker that your holding (need to be out of reach of a block tho or it’ll place the shulker instead)