Ability to add names as collaborator, admin or students instead of sharing the link
Ability to add of only the names who will take the assessment so that it would be truly secure.
For Collaborator / Admin:
Ability add names, sharing the link with someone is a good idea however if is too risky as the link can be accidentaly shared. Adding the name would be more secure. This is similar to what other profesional assessment authoring tool out there being used by big companies.