You said that the absolute wasn't the source of metaphysics, the creator was. However my idea was that there were entitys that were beyond metaphysics, such as pataphysical entitys. The trancendents were supposed to ne beyond metaphysics. The Absolute may be the source of metaphysic, but the creator is the source of everything. Unless we decide to merge them into the same being.
The box also contains every universe, just becouse the box contains a universe doesn't mean that the multiverse doesn't contain the universe. The creator created the absolute who created the demiurge who used the absolutes power to created pysics. however the creator could be like the auther of a story were created the absolute becouse he wanted to start the chain reaction that led to the creation of metaphysics. Plus the absolutes realm is just one part of the box, there could be other parts were the creator directly created metaphysics. In my cosmology the trancendents are beyond metaphysics. If the creator created the box he would be far beyond the metaphysical level in power