It has been with great difficulty and trial and error to find what works for me so I went through many pairs of boots and liners, new and used. Now that I have found one simple solution to my fitting problem I feel I could make any size 28 shell (my feet measure 28.2cm) work very well for me whether UPZ or Deeluxe. The solution: whether using a 28 or 29 heat moldable foam liner, i.e. Intuition, Deeluxe 131 or 141, I have to cut a slit all the way through the portion of the foam liner that covers the tops of my toes, from the top of my little toe across to the top of my big toe about 1" back from the toe end of the liner, so that my toes have plenty of room. With that slit cut, my toes push through the end of the liner so the slit opens up to about 1/2", (12.5mm) wide. No matter how many toe caps or other devices I placed around my toes when heat molding I could never get my toes even close to comfortable in foam liners. Zipfit 28.5 were very comfortable. I have boarded in these modified liners for three 2 hr. days and have had no problem with cold toes although if I lived in a colder climate I might have to find some insulating material to fill the slit with. Even with a 29 shell and 29 liner (I know a 29 is too big and I can't cram my foot into a 27) I couldn't get my toes comfortable. After showing my shells to numerous boot fitter guys it became obvious that a 28 shell, Deeluxe or UPZ, had plenty of room in it. The toe area of the liner was always the problem no matter how much screwing around I did try to thin the toe area out. Much to my elation, boot fit is no longer a problem.
I may extend the slit on each side to give my toes even more room laterally.