we got some pad hardner for our dog, it was actually in France and called Solpad or similar and worked well.It was sold for hunting and working dogs. You put it on twice a day before you start working the dog and it does harden up.
We found shoes are only really tolerated when there is already damage to the paw – in my experience the soft neoprene boots work really well but you will need to modify them to stop them wearing out. I glued strips of cordura strap from an old rucsac to the bottom and they are bomber now but only as first aid. We have some ruffwear shoes, they are beautiful but the dog won’t walk with them for more than 10 mins as they are pretty stiff. They fall off too, the sizing can be tricky on a spindly dog.
Our dog has been on some mega multi day walk up to 100 days in length, her pads are as tough as can be but you can still wear them out. She will always seek out the smoothest bit of the track but sometimes there is no choice and it is just a matter of time before they sit down and won’t budge!
Places with rough sharp paths are a problem and best avoided long term. Limestone chuckies must be the ultimate torture for a dog.