You could edit the template that makes that message appear to include a link to that tiddler. Or a button that opens it in edit mode.
This needs some tweaking but it gets you part of the way there.
Put this in a tiddler (you can call it whatever you want):
<$list filter="[{!!draft.title}!is[missing]]" variable="listItem">
<$button>
Open Existing Tiddler
<$action-navigate $to={{!!draft.title}}/>
<$action-sendmessage $message='tm-close-tiddler'/>
</$button>
</$list>
give the tiddler the tag $:/tags/EditTemplate
and give it a field called list-after with the contents $:/core/ui/EditTemplate/title
Then when you are editing a tiddler and you give it the title of an existing tiddler a button that says 'Open Existing Tiddler' will appear.
It isn't in edit mode and it doesn't correctly dispose of the current draft so there are tweaks that would help, but it may be better than the nothing.