Max # of values in a custom form field?

I'm not sure what the limit is, my largest dropdown "only" has 440 values, but if I click that dropdown and start typing what I'm looking for it jumps to that selection - I don't see the text I'm typing, but it jumps to that item - so that at least helps with limiting the scrolling needed.

There is no technical limitation on the number of values that can be added, but performance may be impacted if there are more than 1000 values in the dropdown. For example, it may take longer for the dropdown to load and for users to scroll through the list of values.

If you need to add more than 1000 values to a dropdown, you can consider using a different type of field, such as a multi-select field. Multi-select fields allow users to select multiple values from a list, but they are not limited to 1000 values.

Here are some tips for using dropdown fields in Workfront:

Use dropdown fields for fields where there is a limited set of possible values.
Use multi-select fields for fields where there is a large number of possible values.
Avoid using dropdown fields for fields where the values are dynamic or change frequently.
If you need to use a dropdown field for a field with a large number of values, consider using a search bar to allow users to filter the list of values.
Use display logic to hide or show dropdown fields depending on the user's selections in other fields.
I hope this helps!