To directly answer the question, it is possible to implement and introduce such feature, as Nitrokey Start’s firmware is flexible, and on top of that - updateable. However I fail to see would that save the situation, like presented in the image. I would guess, that this would escalate it.
I do not specialize in such cases, so please take it with a grain of salt. Instead of clearing the key with the panic PIN, I would thought about another solution - using separate key set per entered PIN. Then one could fool the oppressors, that they have the wrong device, since one complied to their request and has provided the correct PIN (proved by device being working, but not with the given particular encrypted data).