Titan, Ganymede, Europa, pluto, and Triton would all have some major outgassing if brought in close to the sun. It's simply a change in equilibrium state. It was known as the biggest comet until the KBO's started being discovered.

I repeat is Chiron round? That's the issue for the suggested definition. Based on a link from your link with a Diameter of between 148 and 208 km I'd guess not. This is in the range where outer planet moons start to become irregular. I think Neried (340), Mimas (398) and Miranda (240 x 234.2 x 232.9) are among the smallest round Moons. Proteus is even more irregular with a 201 to 218 range in dimensions at a little over 200 km. Even Ariel at almost 600 km is somewhat irregular.

Regards,
Mark