Thanks for the cultural tips everyone! Nice to hear what others are doing that leads to success.
This winter, I tossed my walkeriana into the greenhouse that gets cold but not freezing. Last year I gave it a drier but not completely dry "rest" indoors over winter with shorter light intervals and got nothing. This year I figured I'd see if cooler temps and drier conditions might work, but now I may need to rethink that.
To be honest, I have a couple other Cattleya alliance species that refuse to bloom for me regardless of what I've tried over the years (ex: R. digbyana and B. gardneri), so I was basically giving these things a final winter to perform before they get evicted.