As for keeping the boots cool during a
ride, I simply have him stand for a few in all bodies of water we
encounter (in summer or warmer months). And yes, I do sometimes have to
readjust them, but not as often as you would think. He is not an
endurance horse, just a trail horse, but has done 30 mile rides with no
problems.
The last sentence is the key there. You are not using him as hard as an
endurance horse gets used, even though you do some long miles.
As for readjustment--the support is gone long before you can see that they
need to be readjusted, when the horse is being used at speed. You likely
are not going that fast.
And yes, offsetting the heat as you do is an option--but again, not one
that is always practicable in endurance competition.
I'm not knocking the boots--they are good for what they are designed to
do. They just aren't practical or desirable for the average endurance
horse.
Heidi