I don't know if SAs generally prefer / enjoy serving crossdressers but... Here's two recent experiences (both en femme)
I went shopping in M&Co in Buckingham a couple of months ago. I saw a dress that I liked and asked one of the SAs if I could try it on. She said yes but I got the feeling that she was uncomfortable. A few minutes later one of her colleagues checked with me to see if there was anything I needed etc, very chatty, brought me another dress to try etc. I saw the original SA as I left the store but hot the impression that she was avoiding me. And, yes, I did buy the dress!
A month later, I was shopping in Leamington Spa. I went into 'Roman' where, again, I saw a dress that I wanted to try on. I asked an SA if I could try it on and got an enthusiastic "Yes". This young lady spent the next 30 minutes bringing me dresses, giving her opinion on sizes and fit, enlisting two different colleagues to help etc, etc - on a busy Saturday afternoon! Again I bought the dress.
Don't get me wrong, I've no criticism of the folks in Buckingham. The store there dealt with the original SA's discomfort (and me) in a professional manner. In both cases I got both assistance and encouragement.
