Question for you all. We had our tub valve picked out. Plumbers started working on all their stuff & the concrete slab will be poured next week (no basement or crawl space). GC just told me the plumbers won't be able to install the Kohler Kallista valve down the traxck because the house will be built with a slab. At the moment, there does not seem to be a good alternative. Can anyone with experience comment on this? Thank you kindly!