Definitely the 2.5x telephoto because it is optical, while the main 1x lens at 2.4x is all digital. You'll see the difference if you use Explore Mode in video and use the zoom scroll from 2.4x to 2.5x as it switches cameras. The image will go...
Maybe you didn't get the details right?
DJI has had 1" sensors in drones since 2016 and the Mavic 2 pro had one in 2018.
The Mavic 3 and Mavic 4 have had 4/3 sensors for a couple of years now .. that's almost twice the size of the 1 inch sensor...