Sophie (my mare) seems to be completely fine with being held when facing the wall. She still tends to pull back at random times but then settles when we don't yell at her and simply wait for her to calm down before resuming what we were doing without fuss. And the few times we have tried to tie her up, we have always left the rope slack enough that she can twist and move her body if she wants to. However, as soon as she realises there is a pressure holding her, she freaks out.
We do use the Blocker Tie Ring at my stable and it, sadly, doesn't help. We have tried to keep her tied so it gives it but doesn't break but that only serves to make her panic more until it's dangerous for everyone involved. We don't want to risk someone get hit or Sophie falling and hurting herself while she panics so, whilst I truly wish it worked, I'm sad to say that, that method doesn't work. We are definitely going to be working with her leading as she gets a bit...strong when we take her out and she tends to knock you with her shoulder if the other mares are out and she isn't. However, in our eyes, that's more to do with us being a bit lax with manners and that's something we have to fix separately.
If you don't want to use a blocker ring, outfit her with a long rope and a competent handler who can 'read a horse' and is wearing gloves. Run the rope through a ring and have the handler stand at her head holding the end of the rope. If the mare pulls back, the handler lets the rope run through the ring until the mare stops, then leads her back forward again. The concept is the same. Gradually the handler can stand farther and farther back as the mare becomes more comfortable. I've used this method quite a few times with horses who pull back when tied to a trailer, and it works well. At first I'll have the horse standing about 8' away from the trailer, and as they get more comfortable, stepping them up one step at a time until they're up next to it.
I certainly haven't heard of the method with the long rope and the ring, so it definitely might be worth trying when we are able to find someone who is able to see an event before it happens. When we had her vetting done, the vet did mention there is some part of her eye that's a bit damaged but they assured us that this wouldn't affect her in any way...might have to look into that a bit more to see if there's something they were missing out on.
I'm 100% going to be trying to Ground Tie method as that's probably the calmest way of sorting this issue out, so I can only hope it will help after a few weeks of working on it with her.
Thank you very much x