Just now saw this, your request was in Aug 2020 so maybe too late.
I got the pegs that Crew Chief talks about above, about 3 years ago. The link no longer works and it took awhile to find these pegs again. I got them from MC Motoparts and it looks like they are still available.
TRC Rear Touring Footpegs, 39mm Extension - Yamaha XT 1200 Z SuperTenere 2010-2013
They also have an eBay store.
I've had these on since Jan 2018, 50k miles. We've also done several miles where my wife will stand on really rough roads. We have had no problems with these pegs.
These are listed as being for 2010-2013 models but I checked the rear peg part numbers for a 2013 are the same for a 2021.