In the SimGameConstants.json line27 is a value for "MaxJumpDistance" set to 30. Have you played around with that one?
As long as there is a valid route to a system (does not have to be shortest!), don't fiddle with "MaxJumpDistance". There are significant lore reasons why it is 30LY.
I don't know that an item can trigger a map change. Right now I have only been able to see storyline / even triggers. I would like to figure out using 'weeks' triggers.