Doubtful. Boy, they will say just about anything to make a sale though
why not just tell her it’s majik unicorn foam?? 
Look, if you want a saddle that really fits, actually fits, you probably need someone who knows what they’re doing. Very very unlikely that any of these sales reps truly do. For example, ask them if they have ever had ANY TRAINING of ANY SORT on saddle fit or horse physiology provided by someone OTHER than a saddle company. Go ahead and ask. Any training by someone who was not going to pay them commissions. Unlikely.
And even if you get a rep who knows what to do, your options with these foam saddles are limited. They are not “custom,” they are “customized” and there are limitations. They can put one of a number of tree types/sizes on the saddle. One of a number of flap sizes and configurations. One of a number of panel fills/depths. And that’s it. If that fits, super. If not, so bad so sad.
Many horses do ok with off the shelf type foam saddles but a horse with major back issues and some asymmetry that is telling you clearly he is in pain-- this might not be a horse that can do with an out of the box type foam saddle. Many of them are lovely items but your issue is FIT and it is quite likely that they are NOT necessarily a good choice to get a custom FIT. For that, if you can find a wool saddle that can be truly adjusted, and tweaked as your horse improves, that might be a much better option. If you must have trendy, there is County. Though, honestly, for half the price you can get something as nice if you look at other brands. But if you must have ego fluffing etc. there is a wool option in County.
I’ve just seen SO MUCH bad “fitting” in the French brands and so many people trying brand after brand. If you need a basic saddle to put on multiple horses and you’re thinking more about rider comfort-- sure. But someone who comes to the board and says “my horse has back pain and a diagnosed back problem…” to think the solution is just try a different French saddle… that really doesn’t make a whole lot of sense.
I am sorry that the CWD didn’t work out and that the rep is little help. Not a new story by any means.
Also don’t be so sure the Voltaire is magic. You have been riding in a saddle that hurts. You took it off and put something different on. It is sitting differently. The horse is probably relieved. Doesn’t mean the Voltaire fits or doesn’t fit or that after a week of riding in the Voltaire the horse won’t be sore in different spots. If you take of painful high heels and put on too-small sneakers you probably feel better. But after a week in those too small sneakers you’re going to hurt again.