Properties are told to "go direct" as though the OTAs were a habit to break. In practice the agents deliver real volume and the direct channel is what protects the margin on it.
Running both safely is an inventory question. One pool, one availability guard, and a clear rule about who each constraint binds: a stop-sell binds the whole house including your own desk, while an agent's allotment caps only that agent.
A direct booking request from your own site lands on the same board as an agent reservation, and the same pooled guard decides whether it can be taken — so the site cannot sell a room a group block is holding.
The commercial difference then shows up where it should: in the settlement. An agency booking carries a commission booked as an expense and a net remittance reconciled as a position, while a direct booking simply does not.