At the moment, the Associate to a Jira Issue from Salesforce feature is limited to searching by Jira Issue Key or Jira Summary as listed here. i.e. "STP-10", "This is the summary"
It would be easy to search by Jira Project Keys regardless of the letter case . i.e. "STP" or "stp"
This would benefit when there are many projects and the user is not familiar with all the Jira Issues.