We are indeed working on new jacket designs, and we have a few in the works right now. The current jacket has a 13" diameter and fits nicely with buckets, PET carboys, and plastic BMBs. The glass BMBs however are too tight in the 13" jacket. They fit, but like you've noticed, they can be difficult to deal with. We will be releasing a 15" jacket by the end of the year that will not only fit the glass BMBs better, but will also allow for Speidels (20L and 30L) and bucket style 30L fermenters.
The multi-piece velcro design that went out with the first batch of units was retired for myriad of reasons. It was a neat concept, but unless you installed it very tightly and had zero velcro gaps, condensation would form on the fermenter and we had a number of cases where mold would grow in the jacket because of that. Obviously, this is bad. The all in one design we are shipping now doesn't have this problem, and when we release the 15" jacket, we will still recommend you choose the tightest jacket for your fermenter to avoid mold and condensation forming. If we do bring back the velcro based design, it will be in a far simpler form.