Ran into an interesting situation. A couple years ago, we contracted with a well-thought-of home repairman to replace a shower stall in a rental unit. The tech used a very nice-n-thick fiberglass stall and used an Aquasource single handle shower faucet.
So I get a call from the tenant telling me that the faucet is leaking badly after shut off. I went in and replaced the rubber seals and springs but that would not stop the flow. So time for new cartridge right? Except nobody carries the cartridge ... not Lowes, Home Depot or any of our plumbing supply places.
I ended up cutting out this monstrosity and putting in a old-style delta clone that I can get parts for anywhere. Lesson learned: You might want to specify plumbing makes/models instead of letting the tech make the choice.....
BTW, have you looked over the thin and flimsy shower stalls being offered at the big box home improvement stores these days?? Who carries the good, commercial grade shower stalls today? My tech has passed away....