Pins out of a cat's innards is an expensive operation. Consider the fabric that cost represents. Losing a cat to a pin is even worse than blowing fabric money if you don't have to.
How about an appropriately sized, shallow plastic box with a lid with a catch of some sort? That would corral your pieces and stacks as well as anything else with pins. Only a very little of that fabric money involved. Your pin loving critter could bat at the box, sit on it, etc. and both of you would be well and happy. Well and happy are big words at my house.
Staff for 2 Ragdoll Cats