Mary the tiler has been back along with Tyson, and they took another look at the floor. Surprise, it's not level--there are various dips and rolls. Situation normal in an older house, and shy of going under the house with jacks, not much to be done about it. Betsy just wants me to be aware that the floor won't look perfectly flat, but assures me that I'll soon get used to it. And that the worst dip is about where the island will go, which will help. I think they've decided to use 1/2" backer board instead of the 1/4" to help smooth things out. Mary will start installing the Durock on Friday, and may want to work Saturday to finish.
Last item was about the leftover brick we are going to use to fill in the old door to the garage: there's not enough whole brick in it to do the job in the stack I had saved after rebuilding the carport into the garage. This brick is not made any more (and I'm not going to chase it in salvage yards), so we will use what we have. The result will not match the rest of the wall, but at least the brick is the same, and it is in the garage. I also reminded Betsy that the holes from the old dryer vent and the old electrical meter will need patching while the brick mason is there.