He was going through so much trouble to create a place to hold a sliver of the consciousness of a Primordial for a short while, but Rowan was not displeased. Instead, it indicated to him the severity of the enemies he was about to challenge.
At first, Rowan wanted to hold the meeting at the Inheritance Ground of Chaos, where a literal throne of this Primordial was waiting, but that would have left a lot of power in the Primordial's hands, and he did not understand all the hidden mysteries of that realm to place himself before a vulnerable position like that.
Rowan could risk walking on other Primordial Realms with his physical body because they were still in slumber, but the Inheritance Ground of Chaos was a no-go area for him.