I used the blue tubes only the first year, until they grew out of the top of the tubes. I don't think they will do much unless, as above, the problem is rodents from the ground.
Update on my Wyoming Vineyard. As of today some of my vines have the cordon arms grown out, some just barely made the top wire, and a few that maybe next year will make the top wire. I had a few get stunted by some weed spray, but over the last three growing season I have not lost one vine as of yet. I thought I had lost one early in the summer, but it finally started having some growth.
I did let a vine or two produce to grapes this year, but not many. One thing that surprises me is that my Petite Pearl is way ahead of my St. Croix, and Somerset. I was expecting the St. Croix and somerset to ripen ahead of the Petite Pearl.