Recommended cross-platform Authentication flow

I have a multi-platform game that I want to integrate on Kongregate. I'm using PlayFab as my back-end account system.
The rules state that a Kong game cannot require a game to have third party login, but what about optional logins?
Is it OK if my game logs into Kong by default, but has options to link that account to other services, and options to login to other services (as long as the login triggers a link to the current Kong account)?

Thanks,
Duncan