Ego is not what the framework asks the slave to surrender. What it asks her to surrender is the performance , the armour built for a world that cannot hold who she actually is. Inside a legitimate frame, that armour is no longer needed. What remains, once it is laid down, is not a diminished person. It is a more precisely herself one.
A Dominus cannot know exactly where every limit lies before he has tested the territory. That is not a flaw in the framework, it is an honest description of how this works. What matters is not that the limit was unknown. It is what happens when it is reached, and whether the frame around it is governed enough to hold.
Maledom, as it now exists in virtual worlds, is not dominance. It is the aesthetic of dominance performed for an audience that cannot tell the difference. The men who populate these spaces could not hold authority in a real dynamic. The women who populate them are not slaves but tourists, drawn by a badly written novel and the imagery it sold them. Each rewards the other's incapacity. To frequent these places is to endorse the parody that makes serious dynamics harder to recognise and harder to find.