I will not comment on your case in general but just on quoted part.

I don't see this as a problem. Actually, I consider it as a feature which I already praised in some topic here on forum. I used this numerous times to my advantage to play a bet few seconds after sending BTC. I lost some bets and won some and never had any problems. Granted my transactions always confirmed before the bet was graded. I didn't try to take advantage of this feature, I used normal tx fee and it always confirmed inside half an hour. Never had to pass any KYC and amounts were much bigger, between 0.05 and 0.1 BTC deposits each time.

This is something I would like to see at all betting sites and accepted as industry standard/best practice. It doesn't make any additional risks for the provider (it is clearly written somewhere that you can't withdrew before tx. gets confirmed) and we players have a feeling of instant transactions.