Beneficiary Vs Second Room?

I’m planning a TTR trip this summer, and a friend wants to come along. I want to be able to share my Premier perks, but have separate rooms. Do I have to add them as a beneficiary or can I just book a second room and put their name on arrival? Or another route entirely?

 

Hi Jes
Did you find out how to do it? I also trying to find out the answer.

 

I added as beneficiary since I wasn’t ever able to clarify. Seemed like the safer option.