Solving the cross-tie wiggles

In the last two months I have been doing a lot of groundwork with Rose and she has been completely on board with it. She's now ground tying very well and will not move a muscle when told to stand in the arena or  while standing loose in the barn isle while I groom/tack-up. She's happily following me through the tiny people door into the arena. She's staying out of my space and being very respectful with her head.

However, she's been wiggly in the cross ties. I'm not sure when this wiggle thing really started. I know it was sometime after I got pregnant, and it clearly became a habit. But what is causing it? Some days she's nice and quiet and stands still, but others she's constantly fidgeting in the cross ties. It's not to a dangerous level, just an annoying one. Furthermore  if I leave her in the cross ties but take them off she'll ground tie nicely. So how can I fix the wiggles?

Things I've done, that have had no effect:

1. Ask her to back a step and tell her to stand, every time she fidgets. 
2. Pull her immediately out of the cross ties when she fidgets and asking her to move her feet/back, etc. Return her to the cross ties once she's licking her lips and chomping in acknowledgement, etc. 
3. Let her stand in the cross ties for hours while ignoring the behavior.

Nothing in my bag of tricks was working so last night I decided to try a new approach, thinking that the issue may more that she's developed cross tie anxiety, not so much that she doesn't understand that she should stand still. What did I do? I decided to make the cross ties become her favorite place in the barn. I was happy to an exaggerated cheesy extent, gave her leg and back massages, praised her and stuffed her with horse cookies for standing still.

It worked!

I'm curious to see what happens tonight at the barn, but at the very least it worked yesterday and on top of that I had a great ride. So the mare earned her 4.0 last night. Fingers crossed it wasn't a fluke.

Happy trails and swooshing tails!
•DS•