I dont know about wearing them around at home or walking in them to soften them. When I bought expensive boots I was told not to use them except for riding.
Cavallo were highly recommended to me by someone on NR years ago, but until you put boots on, you really wont know how they fit.
As far as I know, dressage boots should be supple at the ankle - our RI was most particular about that and preferred short boots and half chaps to stiff long boots.
But again, since I dont believe in the old adage of pushing your heels down, I wouldnt make that a reason for choosing boots. If you look at Charlotte du Jardin's website you will see that in most of the pics her feet are pretty much parallel to the ground. In fact the one with the heels pushed low is when she was a little girl and in those days kids were taught to do that.
The advantage of long boots is that the close smooth fit of the leather up the inside of your leg gives you a very direct feel of the horse while protecting your legs from getting pinched by the stirrup leathers. And they may be lighter to ride in which is what I like. They are smooth soled so give less grip on the ground but make you ride better as you have to position your foot nicely in the stirrup.
The disadvantage is that they are soft - so dont give protection for grooming and leading. Having a horse step on your toe wearing fine books can hurt. And you have to keep your legs slim enough (i.e. dont put on weight) to zip up the boots without restricting your circulation and without stretching the boots.
My long boots have been polished a lot using normal black shoe cream - Woly I think. All our riding boots are kept well polished, it softens and preserves the leather. If you look after them they will last for ever.
And I notice that the boots you have chosen have proper old fashioned heels , meaning they can be re-heeled which you will probably need to do every couple of years even if you dont walk in them.
