I suggest that you look at doing the Tortoise Trust Foundation Course (online correspondence - Cost: ~ £40). Its a UK-based organisation geared to keeping torts indoors. There's an interesting piece on microclimates and their importance in long-term health of torts (incl. S. pardalis) in indoor environments. It does appear that humidity levels play a role in growth and one needs to keep in mind that even in arid environs (with an outside RH below 40%), the subterranian humidity levels are generally higher (up to 70% +) where these species shelter, particularly at the base of plants. It is suggested that torts kept indoors in dry, hot environs with a shallow substrate are more active and spend this activity feeding (at higher than normal rates) making them more susceptable to mineral and trace elament deficiencies along with renal problems and bladder stones. Their growth rate is very quick, but not uniform. The same species kept indoors on a deep substrate of loamy soil with live herbacious plantings (and a higher substrate humidity) and regular sprayings suffered no renal or bladder issues and had a more even growth rate with limited to no pyramiding. I'm no expert in chelonian husbandry (partly because mine always sorted themselves out when I kept them in SAfrica), but I've had to start doing some serious homework since keeping them indoors in Europe. BTW - If the female in your first pic is CB, it must be the best looking shell for a pardalis kept indoors that I've seen so far! Well done on that!
P.S. - What diet do you have yours on?