Thanks for the feedback, that's a big help.
I'm starting to get a pretty good understanding of how the modified and unmodified works and your explanation sheds a good deal more light on the matter.
My main concern is how long it will take the Versabond-LFT between the DITRA and the tile to dry. It's a couple days then grout, and a week for light to standard use, then that's cool. I've just heard some concerns from folks that the Versabond-LFT would take "a while" to dry, but I don't know if "a while" means an extra day, or an extra two weeks
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