As has been said, what happened to Mr. Gross could happen to anyone taking communications gear into Cuba. Not worth the risk, IMO. What might be termed "permission" could be easily revoked or claimed to be invalid when entering the country.
Too easy to be accused of being an agent and be stuck there rolling cigars for 20 years.
Then again, Mr. Gross was indeed probably working as a spook under flimsy cover, distributing sat phones and devices which mask their location to Cuban sayanim.
I think if you make the proper contacts, and maybe get a letter OKing everything from the Cuban authorities, you will probably be just fine.