Maybe you guys should try introducing yourselves as if you were new.  That's what I did the first time and I now get a response every time.  Schedules still haven't lined up yet but I am going to keep trying.    

As for Venus, she went to OC briefly but that ad is now gone as well.

I get a response every time I inquire about availability.   I don't do anything special just text the number and usually get a response within 5 minutes.    I know we had chemistry but I would doubt that is it.   I have had similar problems with trying to revisit ladies I had seen and not getting responses.   Probably just timing.

by the lack of patience with some of these newer guys.  We were all new at one time, and although as I look back on my own experience, it seems like an eyeblink now,  it took me three years of being very patient to get approved with all of the bookers in LA and OC.  Of course, I don't use my TER handle or any other review site handle, only refs, so I knew it would take longer.  As you say, there are many possibilities why someone doesn't get a response, but as a veteran like yourself, we all learn to be patient with the process.  Sometimes, there are techniques that work to facilitate a response sooner rather than later, and other times, we just have to keep trying, as you say, or else move on.  

I think one thing that can help is to do what Chef said, and just assume you are applying as a new customer, giving all of your information, refs, etc., in the first contact text.  But like you point out, if she's not accepting new customers, and there have been many girls that have been in this position over the years, you're going to get crickets anyway.