Me too! As a proud Forever-GM I absolutely love Foundation Sentences and think they're an incredible tool for immediately setting the tone and getting player buy-in even before character creation. I haven't run any Realis yet, but my North-star for them at this point is a piece of wisdom I gleaned from FatT itself: "one of the great things about TTRPGs as a medium is that you can just state your themes out loud."
For example, a campaign I'm chomping at the bit to run is going to be pitched with (some variation of) these two Foundations: "Our story always evokes Spring: a time of transformation and new beginnings," and "Our story never solves problems through violence."