IDM 4.9 - prd approval activity - assignee requires to be a trustee on the prd or cannot access approval form

I noticed an issue with the approval workflow for role assignments in IDM 4.9. If the workflow is configured with only the admin user as a trustee and set to "custom approval process" for certain roles, it now requires all approval activity assignees to also be configured as trustees. Otherwise, they receive an error message instead of the approval form:

Do you know a way around it? I don't want to configure all the possible approvers as trustees on prd....