“This is fair compensation”
Why? (I keep on repeating myself) Effort is expended whether there is a date or not.
Results are only a shidduch. Pay for effort (no need to EVER do so in halacha IIRC) or results.
“3 dates is clearly in the ballpark and they shadchan should be compensated.”
With all the checking done, one date is “in the ballpark”.
“the community would benefit greatly if it became commonplace”
You mean those who don’t mind paying (rich who can already throw money at the problem) and shaddchanim. I’m not sure about the community.