Here's my personal take on this:
I started my collection in Animal Plastics T8s with glass fronts. I still have my first four snakes in those T8s, with the rest of my collection in racks in the QT room. It could absolutely be a coincidence, but I only have two snakes in my collection that are known to go off feed, and they're both part of the original group in T8s. Husbandry is as similar as I can make it between the two rooms. Granted, I've only had the QT group - 12 snakes total - for 3 months or so, so it is a limited sample size in terms of time. Also, the two in T8s are in the 1000 gram wall range (and have been for over 6 months). However, four in the QT room are also in that range and haven't refused a meal yet. Needless to say, I'm looking forward to the end of the month and being able to move my entire collection over to racks once QT is over and seeing if this changes a couple of my girls' feeding habits. It might not, but I'm certainly hoping it does!
Edit: I still love my T8s for their display qualities, but the possibility of getting these two girls back eating regularly is my priority.