Ok, the problem with current picker is it is simply a way to quickly select previously used values but still allows free typing over the top.
My ideal solution would be that the product tag field in program settings could be improved to offer the ‘constraint’ methods for the interface within product settings and product tag editor table. More simply put an option to prevent free-typing into the interface fields.
This would be very helpful for interrogations and template formatting options like courses where course is drawn from a product tag as the available options are restricted to options defined in the template and typo/case errors can be forgotten about.
This is what I was getting at with my previous idea on the subject;
I know you gave your reasons why this would not be practical which is why I was trying to come up with alternative solutions which could put the ability to achieve this constraint/control ourselves with scripting if it was deemed a low value improvement when time was considered for you to build it in to the software.