Activate used Lifetime unit

I am waiting on a refurbished 648250 from Weaknees that already has Lifetime service. I have an inactive account on the Tivo website from units I owned in the past. Will I need to activate or register the Lifetime unit? The only advantage I can see if the unit is fully functional on arrival would be if I have OTA RF frequency issues (as I certainly had in the past) or guide problems. Please share thoughts on this issue.