Is it possible to promote the Attach Files menu item to it's own top-level button, in between the current Assign and More buttons?
Yes, an workaround it's possible using this plugin https://marketplace.atlassian.com/plugins/com.keplerrominfo.jira.plugins.blitz-actions(it will be still in the menu, but it will show a button on screen).
Inside of the action, you can use a script to attach uploaded files to the issue.
I'm guessing since no one has replied to this, it isn't possible?
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