Long story short, DM homebrewed an item that would double the WIS modifier that's included in a monk's Unarmored defense:  While not wearing armor and not using a shield, your AC equals 10 + DEX modifier + WIS modifier.

I know I can create an item that adds a fixed amount to Unarmored Defense, but ideally I'd like a way for it to be dynamic and change automatically when/if the WIS mod goes up or down.

I've been fiddling around with the magic item creator for a bit and it seems to me that the functionality to do this doesn't exist.  Does anyone have any insight? Thanks in advance.

Modifier: Bonus→Subrtype: Unarmored Armor Class→Ability Score: Wis

Whenever you add anything to, change anything on, or remove anything from any homebrew, you MUST re-save the entire project using the main [SAVE CHANGES] button under Basic Information or the system will not pick up your changes. After that it can sometimes take up to 20 minutes for those changes to push through to the character builder/sheet.

The only hiccup is that Monks already add their Wis to their Unarmored AC, so the system might not be able to double it (I’ve never checked). But that’s👆the correct Modifier to do the job either way.

Thank you!  Yes I am very familiar with saving and waiting.  

My question was focused on whether it's possible to double a modifier.  Since the monk already receives a WIS modifier bonus to unarmored AC, the magic item.....well now as I type this I realize the bonus doesn't need to be doubled...just added again.

Thanks for replying....I think you've set me on the right path!

Confirmed.  Modifier: Bonus→Subrtype: Unarmored Armor Class→Ability Score: Wis   This was the way to go.  Equipping (and attuning...missed that part) added WIS modifier again which effectively doubled the WIS modifier for Unarmored Defense.  

Thanks for your help!

Thanks for confirming that it worked, I appreciate the information.