Post O365 Migration - Outlook Custom Form Fields No Longer in "User Defined Fields in Folder" list

I recently had my IT vendor complete an Office 365 / email migration from one Office 365 vendor directly to Microsoft Office 365. Prior to the migration, I had created a custom contact form in Outlook that had approximately 100 custom user-defined fields that, when I created them, were placed in the “User Defined Fields in the Folder” list. Post the migration, I’ve been able to successfully migrate and publish the form, and each contact record kept the data in the custom fields.

However, my problem is with mail merge - I often use these custom fields for mail merge documents, and since the custom fields within the form are not listed in the “User Defined Fields in the Folder”, the mail merge document / email can’t grab the fields or the data in them.
I’ve read many articles indicating that “User Defined Fields in the Folder” do not migrate, and that there is no method to bulk-import them into the folder to populate that list to be used for mail merges. So 2 questions:

  1. Is this the case - that there is no way to bulk import / create User Defined Fields in the Folder if those fields already exist within the custom form?

If so, then,

  1. What is the best way to re-create approximately 100 user defined fields, many of which have complex parameters (such as limited validation options, etc)? Is there a way to modify a custom field and save it so that it gets placed in the User Defined Fields in the Folder list? Obviously, I’d like to accomplish this task in as little wasted time as possible.

Thank you in advance for your help.

Mark

So, after fiddling around with this a bit, I stumbled upon a solution that worked relatively well. I pulled up the custom form in Developer mode, and right-clicked on each custom field to select Properties. I then created a New Field with the exact same name, type, and format. However, instead of selecting this new field, I just cancelled out of the Properties window to leave the form to use the custom field.

Somehow, the system is now linking the newly created Field in the User Defined Fields Folder with the custom field I had previously created with the form, and the data in the field is populating both the new User Defined Field in the Folder and the existing custom field. Better yet, I can now use these fields and data in my mail merge for emails and documents.

I’ll post an update if I run into any more challenges, but so far, so good.