Fair enough, as I say I havent seen the class, I am glad it is making him better

from what you describe I would be tempted to not really ask him for anything in the off lead bits - basically ask him for focus and stuff before you unclip the lead, then ask him for something simple then send him off to play - dont do recal or anything at that stage as you cant really reward anyway
When you need him back just go and get him

I'm inclined to agree with you.

Well in all fairness other dogs should not be allowed to come close when you are rewarding him.

Yes you need to keep Cain closer so you can drop the line and if he loses interest in you and starts to leave your side step on the line and you know you need to work harder to be more interesting.

I'll take you on a little guided tour of Horton one day It's not amazing but it doesn't feel like London.

Yes, I can see your point about not wanting him to approach other dogs in the first place.
I know it is not at all the same; but to begin with Kestral would charge barking and snarling at people who were in the distance. Over time as she learned to relax and learned she got food (but as you know shes obsessed), she just stopped becoming hyper-vigilant and the behavior has pretty much ceased.

I know its not the same, just saying, perhaps one day when he sees a dog he will look to you for direction instead of barreling in. One can dream anyway!...
I think your clicking for looking away thing is good for teaching some control?

I kind of agree about not recalling him too much if its safe not too. A bit over board but I reward for almost 100% of recalls as I want a keen recall.
Not rewarding when he puts in so much effort to drag himself away from another dog must be tricky. Totally understand the rule though.

If there is ever anything I can do to help I am a willing stooge!
Good luck

What about having him on his longline but having an even longer one clipped on at the same time - you can unclip the shorter one and have the really long one attached and he may not realise.
You'll have to pop over to check out the fields here - the one immediately behind the house is good, visiblity is good because it's raised in the middle but drops around the edge so I tend to stand more in the middle and the dogs tend to stick to the edge, means I can spot other dogs before Casper/Kiki does. There's a field further in to the walk that's absolutely huge and only has 3 exits - one being a private gate that appears to just lead onto a field and a couple of houses and the other two being tucked away so the dogs wouldn't necessarily remember where to bolt to when offlead. I'd be happy to go along and if you had Liam with you, we could all cover the exits just incase So far I've found the local walkers to be great at avoiding a dog on a longline too which helps.

Definitely do need to come and check out your fields I may just move in, it would solve a lot of my problems. Room for a lodger?

Got a sofa and garden table out in the garage..you can roast your dinners on the fire pit

In case anyone is interested, my class have kindly offered to set up a 1:1 session with just Cain and the teaching dogs to see how he behaves around them and also to put in some recall training around the horse.

Sounds like a plan to me.

Sounds perfect Let us know how it goes