You will likely end up spending triple the cost of a third party kit only to have one button on your fob but no additional functionality.
- price of the 2021 FOB (X2)
- price of the 2021 remote start controller
- installation cost of the controller in your 2020 Telluride
- each Telluride can only have up to 2 proximity FOBs programmed at a time, so cost to have the two new ones programmed to start the car and then remote start button configured which can only be done by a dealer likely a couple hundred $$
Versus the alternative, buy a decent aftermarket remote start unit (ideally a plugnplay one) that works with the existing 2020 OEM remote FOB requires no reprogramming. You just train the remote start system to start when the OEM lock button is pressed three times. This entire option may cost the same or less than just the cost to reprogram.
Another thread on this forum found this kit:
2020 KIA Telluride Remote Start Kit - PUSH START ONLY I think someone mentioned reprogramming the proximity FOB costs $300 at the dealer.