Nice; I've brought it up before, but will add more here. I went to a glass lecture by a (technical) rep of that museum, and asked about the myth that glass is slightly fluid over the centuries. It sounds silly and he did deny it, but there is various supposed evidence out there. After the lecture he was nibbling at an appetizer table and I got more explanation on what accounts for that misleading evidence and how it applies to Roman glass.
Bottom line is that the topsy-turvy Roman glass at our local museum is that way because they (or their donors) could only afford cheaper objects, not because Roman objects wilted in underground pressure and volcanic heat. Or at least our museum had other priorities than than premium Roman objects and the security they would need. The post above has slightly asymmetrical blue objects but ours just scream asymmetry.
BTW, I had no idea that lecture would have a Roman connection but went because it was held in an outrageous "arabian-nights-like" mansion of the once richest women in the world. The estate hadn't finished being converted to a museum, but I got on an email list for stealth events there (no outsiders allowed to drive or walk in that neighborhood). The very rich/artistic audience showed little comprehension of the technicalities of glass, so the speaker seemed to appreciate my odd but at least on-topic line of questioning.