Fire derivation is the source of all fire, if the user dies, all fire would cease to exist. But this power is also used by fire embodiment and vice versa. So its really up to anyone to decided which is stronger.
But we aren't discussing Meta ability creation, we are talking about CA, which possesses all powers/abilities. CA is just omnipotence but split into infinite parts in the form of abilities (the capability to do something), so some will be omnipotent-level (like metapotence and ultipotence)
Well, the time user would be trapped in space, while the space user would be trapped in time. In my opinion, the time user would win since the space user is unable to do anything and the time user can either look into the future to prevent him getting trapped in space from ever happening, or reverse the absolute hold.