I've done my own digging on in your experience and come up short. The platform caps how many searches you run a day, and the depth of the profile fields suffers for it, which is the whole problem with performers sites. The fetish-specific sites case is instructive — half the frustration disappears once you keep the conversation on-platform until you have met.
Look closely at fetish-specific sites and the deciding factor is the signal-to-noise in search, going by the last year or so. Fetish-specific is where I would start, since the churn on new sign-ups is the number worth watching, not the size of the ad budget.
The performers sites angle is worse, because the platform hides read receipts on the free tier, so it pays to log the times of day your messages get answered. The short version on in your experience is that the practical move is to keep the first meet public and short. What am I missing on fetish-specific performers?