Not sure how much room there is in front of the horse as I am in Australia and have never seen an Ifor in real life and our floats I am sure are different but for example mine has about 2 1/2 feet between the tack cupboard and chest bar so when I travel youngsters I remove the chest bar and have...
No masks fit my Arab mare apart from the Cashels in Arab size, they are all too narrow across the forehead and annoy/squash her eye whiskers or too big around the jaw if I size up....you could try the Cashel quiet ride version which are a finer mesh and black for visibility while riding?
Take the chest bar and have the trailer set up with a solid wall in front of her like a truck bay? She can rear all she likes and nothing to go over then.
2 years is a long time for a horse or any animal for that matter to be having health issues and I imagine it would be draining on yourself both financially, physically and mentally.
I would never expect a vet to provide emotional support as I feel they see so much sadness and death already...
I travel mine to stud or shows for up to 6 hour each way same day. Often only staying at the location for 1/2 hour to an hour in the case of covers.
Just drive carefully so as not to knock them about and offer damp feed and water regularly.
https://www.bitbankaustralia.com.au/pony-bit-collection/
not in the UK but there is a huge range of pony specific bits with good bitting info. Most of these you could source in the UK much easier than Australia.
Oh yes, I also had ten at one point...
I sold a few and got down to a more reasonable number and then I brought another and put two in foal... so now will have eight again come spring...
At least the foals will be sold and help fund the others...
Maybe try some natural horsemanship style bonding exercises? (I am not a tree hugging natural horsemanship fanatic but some of the basic principles are very much useful and I prefer to call it common sense horsemanship).
I have a mare who was very much the other way, lived a wild and free life...
You can just add a regular reversing camera kit to both inside the float and inside the float and buy the corresponding split screen enabled monitor for the car.
It works our cheaper than buying a 'horse float' camera as you are not paying the horse mark up.
Take it to an auto electrician to...