Sah48.....that's exactly what I'm experiencing with my set up. Do you know what they did for an "adjustment"? I've read that others had similar issues and after an adjustment , much better. I wasn't so lucky yet.
I still have the original pictures along with the last ones that I sent with my seat. I'll see if I can see something different with them.I want to help Russel help me get fitted properly, its not going to easy since I'm so far away.
I have the vinyl seat covering and it is quite easy to slide on but if I was planted in the pocket like I should be, it would take a lot to slide forward I'm thinking.
I already have heli bar risers. Luckily i do to, as i'm reaching to far for the handlebars now. Definitely more reaching after the adjustment.
I've tried raising and lowering the seat with no real change. I even tried the front in the mid and the rear in the low . That helped a little, but still not planted in the pocket.
I also have to slide ahead when coming to a stop. I can't flat foot in the mid position even way ahead on the seat so I leave it in the low position. The wings do keep you higher for sure, the left side wing still has the higher than the right side feeling. I'm not liking this seat with how much I paid for it. But there is one more chance to get comfort.

The reason I bought this bike beside liking the looks is that I was able to sit mostly upright. The opposite of a racer. I find I was slightly forward of upright on the maiden test drive. Perfect for my sore back.Now with the latest change , I am forced to reach farther for my bars am leaning forward more than I want. I'll tell them I need to be moved forward for sure. The builder did say that he probably shaved more off the rear than he should have . Funny thing is , I wasn't aware that my sitting position was going to change on the first adjustment.