I don't typically use RKT.. so while I was at the cake store I picked up a block of RKT. I just needed to cut out some flat shapes. is there a way to speed up the hardening of the RKT? (Was thinking about putting it in the fridge or freezer.. but wasn't sure if anything funky would happen to it). I want to cover it with melted chocolate before I cover it with fondant.

I cut out the shapes last night and this morning it was still very soft and pliable. They will be placed on the side of the cake (arms of a robot)... any tips or tricks to making them harden up?? TIA!

You should put it in the fridge, it hardens up rather quickly. I've done it a bunch of times.