To avoid pyramiding we all know to keep their shells hydrated and have a humid cilmate. Anyone ever tried a thin film of vegetable, or olive, oil on the shell? Sounds ridiculous i know but also sounds logical....to me.
Actually yes, some have done experiments with those kinds of things and also the shell stuff they sell. I can't recall the name of the shell stuff, but no doubt somebody will come along shortly and give it.
A forum member (Tom) did a well designed experiment looking at shell growth in the presence and absence of the marketed shell cream (not any food oils). I can't recall if the results are in, but have a look around and see if you can't dredge it up.
As to if it is good or bad, it seems some had good luck with it and others seemed to but did not continue it long enough to tell. Another factor is also to keep in mind, these folks were doing all the things correctly to give their hatchlings the best start, so that helps too. I know some also as I recall have talked about having some problems with ants being attracted to the tortoise more with the covering and a couple of other negative issues.
I don't like the idea of covering the whole shell with oil. It attracts dirt/dust and it may cause the tortoise to overheat. Rather, what I would do would be to take a Q-tip and only paint the new growth spaces between the scutes. I've used mineral oil for this purpose, but you could also use olive oil.
Same goes for Vita-shell, but some folks use that with no problems.
My Tilley is about 5" big and hes got small pyramiding already, I havent seen it progress. I've resorted to just spraying him down with a water spray bottle when I havent soaked him. I also know that my house 'could' have hard water...kind of been noticable after showers or having washed my own hands. I only thought of this idea because if my water is drying my own hands...lets do the math with a turtle shell.
I use VitaShell on my Red-foot after every other forced soak. I rub it on her shell and legs. Sometimes her head when she allows me. I like the results. Plus it softens my hands too. I do mist her a few times a day. I keep her hide box and enclosures moist by misting and pouring water on plants and into the substrate. I do a forced soak every 2 to 3 days. Which means she goes in a container with water to cover most of her shell with no rocks or ways to climb out for about 20 mins.