popa_bar_abba-
If a potential couple do the check the date before it starts getting serious (obviously different for every circle, in my circle it was after the shadchan is dropped), it will also eliminate the need for counseling by a rov.
Checking before the first date will be a gross misuse of tzedakka funds, in my opinion, as statistically speaking a first date usually gets nowhere and generally speaking people aren’t too emotionally attached after two or three dates to be devastated.
Like I mentioned above there are cases where blood has to be retested at a great expense where the parties involved don’t even know what is going on in the background.
Of course if you are part of a circle that has different needs then the above doesn’t apply.
But if you are in doubt just give them a call, they’re there to help.