Should FBI be allowed access to encrypted iPhone data when the they have obtained a valid search warrant?

Should the FBI be able to force Apple to create an override for the delete after 10 wrong password entries feature on the iPhone to allow the FBI access to encrypted data when the FBI has obtained a valid search warrant?

NO. That would be ridiculous. They don't/can't make pen manufacturers make tools to decode anything written with a pen.

So you are really asking 2 questions:

1. Should the FBI be allowed access to iPhone data after getting a search warrant? Yes, absolutely.

2. Should the FBI be able to force Apple to find a way to defeat their own iPhone security measures? HELL NO!