I signed up to Revolut when they first launched. Back then the cards they issued were not contactless. All cards issued from June 2016 have included the contactless feature. I never really felt the need to have contactless on my Revolut card as I mainly use it in America and around the poorer parts of Asia. In America I find they normally swipe and don’t ask for a signature for low values so it is as fast as contactless. In Asia most of the countries I travel to wouldn’t support contactless. However, on my recent trip to London I decided I would use contactless -mainly for the tubes and buses. While I have an oyster card, you can also use a contactless credit or debit card to tag on and off at every stop which is charged at the same rate as oyster cards and the daily cap is applied. Using the contactless Revolut would mean I wouldn’t need to worry about keeping a balance on my oyster card.
Revolut have recently introduced Spare revolut cards. You can now have two physical cards linked to your account and up to 5 virtual cards. You can use these cards in unison or disable one and keep it as a backup. In my case, I would use the contactless card as my main Revolut card and have my old non-contactless card disabled on the app as my backup. I would still bring it with me when travelling but leave it in my rucksack and only activate it should I lose my contactless card. You can also have multiple virtual cards linked to your account to use online.