Is there a preference to change the cursor style to a vertical bar instead of the default block?
Not currently. Core Shell was born with block cursor only, no particular reason for this, just if not necessary, not by entity.
And actually you're the first to ask for vertical bar cursor, would you like to tell your experience about cursor shapes?
Yang
I always change the cursor type in the default terminal app on Mac because I have a hard time remembering which characters the block cursor is actually between. Is it at the beginning of the block or the end of the block? I always seem to type or delete in the wrong place. And maybe this makes me sound like a complete noob, but I just use the command prompt so infrequently and I'm always worried about many other things when typing commands.
So instead of various cursor shapes, you actually would like to have a blinking or colorful cursor?
No, I don’t need it to blink or change colors, I would like it to be like an I beam that is clearly between 2 characters.
The character being typed is where the block is. Not before and not after. It's exactly in the block cursor position. If you type something and move the cursor back with the left arrow key you will see the character covered by the block cursor as it becomes transparent. When you then type a character is inserted in its space. What is different is how you delete characters. It depends on what delete button you use and what type of keyboard you have.
@littleluce with latest version 2.5.1, cursor shape can be change to Vertical Bar or Underline style from Preferences.
Please give it a try and let me know your thoughts on this 
Yang