i'd just like to correct a mistake: you don't need to cap moon scrolls or sun scrolls to achieve this.

you can hover over the flame to see the required amount of moon and sun coins that you need to renew the buff, as well as the dead line by which you need to achieve that amount:

as you can see, capping moon scrolls is not a requirement. neither is capping sun scrolls (you only need 5k suns to renew the buff)