Angel had demanded her "payment" before the ritual began not because she feared the Abrahams would run off afterward, but because she was worried that, once Bethel Abraham revived through one Key of Stars, the powerful force of convergence would make him instinctively try to accommodate the other Sequence 1 characteristic present, drawing it straight into himself.
Him losing control would be the lesser problem. If he didn't, things would get troublesome. I can't exactly kill Mr. "Door" the moment he revives to recover my payment. I might as well just seize it from the start... Angel muttered inwardly, patiently waiting for the Abraham descendants to make their decision.
With her current power, even if these Apprentices before her, none of whom were even Demigods, used their own abilities or Sealed Artifacts to teleport, only corpses would arrive at the other end. Even if they somehow escaped, a curse transmitted through their bloodline could reach every Abraham descendant and kill them without a sound.
After learning of the Primordial Demoness Cheek's rather twisted possessiveness, Angel even suspected that this God's curse was why so few descendants of the Blood Emperor Tudor remained. She did not want any descendants who did not share both her and Tudor's blood to exist, giving Tudor any chance of revival without her help.
While Angel reflected on Cheek's extremism, Dorian and the other Abrahams exchanged furtive glances, raising no objections to the demand of this angel serving the Fool.
The ritual was already fully prepared, and the Key of Stars that held the Abraham Family's hopes of revival had been placed on the altar. Since she only wanted the other one as payment, that was effectively a guarantee that the ritual would be completed.
Having made up his mind, Dorian carefully handed Angel the Key