jira.issue.editable is not obeyed by "Import Steps"

We have an approval workflow for tests that results in client sign-off. At the approved state, the jira.issue.editable property is set to false and no changes can be made without transitioning the issue back to draft.

If you click on "Import Steps" and bring in steps from any source, they are written into the steps list.

To Reproduce:

Create simple workflow. On last status, add the jira.issue.editable property and set the value to false. Move a Test issue into this status. Click "Import Steps" and import more steps from, e.g. another test.

Actual Result:

The steps are added to the issue (and are then read-only).

Expected Result:

The "Import Steps" button is disabled or missing when jira.issue.editable is set to false.