Help with hockey skate topper

I need to make a hockey skate topper for a baby shower. I made the boot of the skate out of RKT covered in gumpaste. I’m having trouble with the blade though. I’ve tried gumpaste (Nicholas Lodge recipe) and pastillage (Elisa Strauss recipe), and they are both cracking after at least 24 hours of dry time when I go to attach them to the sole of the skate. I made a second sole for each boot to attach the blades to so they can dry upside down… I’m not trying to attach the blades with the weight of the boot on it.

I’m open to any suggestions if anyone has any. At this point I’m almost thinking I’ll just cover some foam board in gumpaste since the cake is being picked up on Saturday.

Thanks,
Melisa