How many actual buyers will see this in the private phase versus on the open MLS?
You want a number. Not a hand wave, not a "lots," not a "our network is huge." A real agent will tell you, plainly, how many qualified buyers their office and network can reach — and they'll tell you honestly that it is a fraction of what the open MLS reaches. Fewer eyes means fewer offers. Fewer offers means a softer price.
Red flag Vague answers like "a lot of buyers," "we have a huge network," or "you'd be surprised." Surprises are not a strategy.