Sorry, but that is a cop out. You want to play this card because you have no actual valid reason for your claim.
Your reference system creates HUGE personal risk for clients so don't you, the SP, dare say that it isn't a clients place to comment on the fact that the claimed justification is stuff and nonsense.
Clients here have a right to hear that it is purely an economic benefit try SP's, that reduces no shows, so that they can make an informed decision as to whether they want to take on personal risk for your financial gain.
Clearly there are many who are willing, but it is unreasonable in the extreme for you to try and shut down the discussion with this "only an SP can comment" BS.
You either can explain the benefits in clear and understandable terms or you cannot.
Once you have finished blowing your mind see if you can respond. This is a serious topic with serious consequences for everyone. It needs to be discussed openly and bluntly and without any bullshit about who is or isn't allowed to comment. We are all impacted.
First you admit that the reference system is full of holes then you try and save it with this classic, hysterical "but any extra step helps".
So let's talk about the specific cases your reference system would catch: no shows, people who are oblivious to their lack of hygiene, people who are oblivious to their lack of personality or their abrasive personality.
That is who you will screen out.
Here is who you will not screen out: anyone intent on robbing you, anyone intent on abusing you, anyone who is conscious that what they want to do is unacceptable. All these people will easily find a reference that will satisfy your check because they KNOW what they are doing isn't acceptable.
You are only going to screen out people who are unaware that they are unpleasant, and no shows.
As for your no condom guy let's be clear that after you declined him he can do this: go see another SP and behave well, using a new phone number. Then rebook you, pass your reference check, and then what?
As an SP you already know that you need to physically check for the presence of a condom when you change positions. You cannot rely on references for that!!
If you aren't physically checking then odds are that bad client has already easily gotten past your pointless reference check and you don't even know.