Currently, there seems to be 2 ways to update custom values, go to settings > custom values and "hack away" or build a form somewhere else and use Zapier/Make to update custom values through the API. I would like to suggest that GHL add the custom values to the form editor to allow us to create a form that will allow us to edit custom values in a slightly more controlled way. So allow a form created in an account to update the custom values for that account, that is my ask.