Hello Michael,
Congratulations with the new Yucca hybrids.
Everyone of the hybrids sounds very interesting, and those which has filamentosa genes would probably be hardy almost every where.
The hybrid of Yucca aff. baileyi (fh 1178.9) x Yucca thompsoniana may be hardy in many places, if planted in a good microclimate. It will be interesting to see if the probably narrow leaves will have "teeth" or fibers in the edge.
I think fh 1178.9 is a "green" form of Yucca glauca, but which very much looks like a Yucca baileyi, here in our garden in northern Denmark it is proven to be quite hardy and grows a lot faster than most glauca/baileyi forms.
Please keep us informed within the next years how the plants grow and look.
The page with Yucca hybrids from the 21st. century is updated http://www.bennyskaktus.dk/yucca-hybrids-21st_-century.html
Kind regards
Benny M. Jensen