Supposedly they retain the propulsive landing capability and could try to use it in an emergency if the chutes failed catastrophically. The thrusters needed for it have always been there because they are the same thrusters used for the launch escape system.

It's not 'supposedly'. It's a feature they officially gained just a few crewed flights back. It's a mean of last resort and has to be manually committed to during descend. I assume it may have to cut any remaining or semideployed parachutes.

I could be wrong but I don't think its been tested.