What a terrible law ... but what do you expect, it's horse racing? Even most of the industry leaders have no understanding of the betting aspect of the game.
If ADW's are forced to comply ... it's a whole other ballgame.
But, the law is primarily more of a nuisance than anything else.
With the low minimums of today, it's not hard keeping a net payout under $600 per winning ticket. Obvious exceptions being most Pick 4's, Pick 5's, and Pick 6's.
You can still hit a race for several thousand dollars, but just hit it on several tickets...and go sneaking around cashing them one at a time with different clerks.
It's a greater nuisance if you're an ADW account holder. Now, you'll need to open up several different ADW accounts ... seed them all with money, and play a little bit with each account to still be able to score out on a race and avoid the withholding.
It's an especially stupid rule because you're forcing bettors who already face mind-blowing high takeout rates ... to go sneak around like they're doing something shady and wrong ... in order to avoid suffering further penalties.