Replying again, disappointed. (I'm really hoping I am just doing something wrong here)https://experienceleague.adobe.com/en/docs/workfront/using/product-announcements/product-releases/release-25-q4/25-q4-admin-and-setup - Multi-select external lookup field type added as a new field type selection pe...

Hi Stan255, Yes it's possible and it's actually now pretty easy using validation logic. Here is an example, you need to go to the Add Logic button at the lower right side of the field you're working with, then click validation logic in the left menu and add this to the formula area. Feel free to twe...

Replying for posterity:Idea: Support Rich Text in External Lookup Fields  Idea: Allow External Lookup Fields to utilize a "Select All" button  Idea: Allow for External Lookup Fields to Act as Display or Skip Logic Activators 

Description - Rich text fields have a few oddities when they are used in an External Lookup Field interaction. Rich text fields can cause External lookup fields to fail to be able to be selected OR result in an output that is not user-friendly.   Why is this feature important to you - The more consi...

Description - Allow lookup field results to serve as the basis for display logic within a custom form. (Especially $$HOST-based fields) Why is this feature important to you - This would bring external lookup fields to parity with other selection-driven logic on other field types in Workfront. How wo...

Here is a link to the idea I posted about this feature. It comes with a bonus request for a fix within the request itself! 

Description - When using a $$HOST-based external lookup field and maintaining a data table, such as a list of US States, users currently have to click on each valid option that appears in the picklist for a multi-select-allowed External lookup field.  Why is this feature important to you - This will...

Here is a link to the observations I have on External Lookup Behavior as well. Now to go post the idea! And probably a few others!

Agree wholeheartedly. Inconsistent user experience for functions within parts of the same platform, especially something as closely related as projects and project reporting. If it works on the details section of the project custom form and can be referenced on the columns of a project report (notab...