I think the Kensington scored equal to the equilibrium if I remember (only the guardian scored over 81%) and the riding sunglasses (which I have) were something like 65 instead of the advertised 100!
Mine is now on Nupafeeds seabuckthorn, early days but she's looking really well on it. I...
Same problems here and flies were getting in, I saw them and she actually had a bite on one eyelid. After reading the testing on David Marlin I switched to the equilibrium, it only scored 10% less (81% as opposed to 91% for the guardian) and I've stuck a couple of strips of white gorilla tape...
I've got a couple for my eru girl but have switched to equilibrium as they only block out 10% less (according to David Marlin's tests) and the flies were getting underneath the guardians as there's no stretch to them. I think she's enjoying the slightly better view and is ok so far. I'm sure...
And a libbys webbing version, I have the libbys, its nice.
https://www.ebay.co.uk/itm/Libbys-Scawbrig-Bitless-Webbing-Bridle-Brand-New/303487036644?var=602701020153&pageci=664ec534-5912-4fac-ad28-6248d946aab4&redirect=mobile
A western bosal doesn't tighten, its just a big knot underneath.
Here is a leather version. https://www.charliesproducts.co.uk/shop/bitless-bridles/star-bitless-bridle-scawbrig-style-bitless-bridle-and-reins/
It's a really hard thing to deal with isn't it? I'm feeding mine sea buckthorn from nupafeed at the moment and I think it might be helping. I miss her face too, now she's always masked up.
I am extending my sympathies as mine is going through a flare right now (uveitis is just awful to deal with isn't it?). I saw flies crawling into the guardian mask; as there's no stretch to them it's impossible to have no gaps. We are now in a duct taped equilibrium.