I thought about it and I can happily say that this will never work for these reasons.
If we were to make it only allowed in a special day, that would mean that it isn't allowed in a normal day... But, what is "being Nazi"? If a T breaks the rules and you kill him, of course you can't be warned. If you don't let a rebelling T back, of course you can't be warned. If a T jumps when they are meant to be buttonfrozen and you kill them, of course you can't be warned. This is what everyone defines as being Nazi but it doesn't really mean anything. It isn't expected that CT's let you back when you make the decision to rebel. There is no such thing as being Nazi...
If we were to make it only allowed in a special day, that would mean that it isn't allowed in a normal day... But, what is "being Nazi"? If a T breaks the rules and you kill him, of course you can't be warned. If you don't let a rebelling T back, of course you can't be warned. If a T jumps when they are meant to be buttonfrozen and you kill them, of course you can't be warned. This is what everyone defines as being Nazi but it doesn't really mean anything. It isn't expected that CT's let you back when you make the decision to rebel. There is no such thing as being Nazi...