At the moment, you are able to add additional fields (System or custom field) to the Issue Collector Form. However, it would be convenient for an admin to set a default value for a specific field (Ie Affect Version, Component, and etc).

Scenario:
There are some cases where a user, who filled the issue collector form, is not familiar with a component field. That user might enter a random component while JIRA Admin knows exactly which component to set for this particular issue collector form. Therefore, JIRA Admin would like to be able to set the component field by default (read only).