Hello, before I start i just wanted to say that reading through all 71 pages of your build is what has convinced me to join this great community all of the positive comments and helpfulness of this community is truly great and humbling. Your craftsmanship and attention to detail is truly inspiring.
I do have a suggestion for what you're trying to do with lifting and lowering your bed. Have you considered using a system that is designed as a garage storage lift. The system uses a single motor and a bar with cables to lift the bed. The pulleys used to guide the cables can be mounted into the roof using the roof struts as a secure mounting system. I've included a Youtube video of the system that I am talking about it is built into a tiny house but the concept is the same as what you are trying to do. This may be a less complicated system then trying to wire in two winches to operate at the same time. The video appears to use the same type of guides that you are currently using.
https://www.youtube.com/watch?v=ZEurdaURavwThank you for taking the time to read this and for sharing your build experience with us.
Have a great day.