Can you downshift while car is in motion with a cvt transmission?

Downshifting is safe, you will only encounter problems in situations where you transmission is overheating. The CVT is much more advanced than other transmissions. The Transmission controller and Engine ECU would work together to ensure that everything is all systems go during accelleration and deceleration.

expanding this idea further. there are very sensitive sensors that monitor any type of slippage or problems with the CVT belt. The transmission is a highly pressurized system just to operate, how it runs doesnt really add more stress. The ECU will not allow you to do anything that will harm it.