Depending how far you want to go/ how much of the dash we have to take off I would be willing to reserve a day to pull the larger display from my 2014 and see if its plug an play to your 2015 for others info. I will check the FSM to see how much effort this looks like it would take
edit: I just checked and its not hard at all. Remove the trim around the AC controls then the lower center console, AC control unit, Nav/Radio unit (4 screws) and then 2 screws to get the display out. Had this all apart not long ago easy job.
I'm wondering if I could tug on your ear on this. I recently had my 2014 4Runner SR5 Clock display go out. And I'm looking for information on how to go about removing the dash and or sections to get access to it to troubleshoot.
Any help would be much appreciated.