I currently have a complimentary Clear membership through the UA 1K benefit and would like to add a couple of family members to my account for 50/year. How does one go about doing this correctly when the said family members have their own paid Clear memberships?

1. Do I tell them to cancel their own accounts first before I add them?
2. If I pay 50/year for them on my account, can they get a refund for the remaining months of the membership somehow?
3. How can I avoid having them go through another round of biometric enrollment at the airport? (Is it possible to seamlessly maintain membership benefits for them?)

Thank you!