Description - Bulk-editing tasks does not handle disparate custom forms well. If 2 or more selected tasks have different custom forms, instead of showing the union of the custom forms across the tasks, it doesn't show any of the disparate tasks. On top of that, you cannot remove or edit custom forms in bulk if the same custom forms are not on all the tasks.
The better approach is to show the custom forms that exist on all of the tasks, and only apply the changes to the tasks that have the edited custom form. Showing all of the attached custom forms also allows for removal of the custom form on those tasks that have it assigned.
Why is this feature important to you - It is impossible to bulk-remove custom forms that are not on all of the selected tasks. It is impossible to bulk-edit any field on a custom form that is not assigned to a task in the selection.
How would you like the feature to work - Instead of excluding the custom form because it is not on all selected tasks, show the custom form and only apply the changes to those selected task that are relevant.
Current Behaviour - Custom forms that are not on all selected tasks are not shown and are not listed to be able to remove them. Users must find and select only the tasks that have the custom form to be removed or bulk-edited.