Thirty years ago, people said the same things about Monart. Obscure unknown, poorly made made gaudy junk with no possible interest for collectors.
When I started putting it out on stalls in the 1980's people were amused, some would come and ask if it was Ruskin (pottery). The professional glass dealers were appalled. It was not French! It was not classic English! It was rubbish.
So what changed? The glass remains obscure, poorly made and lacking in aesthetic appeal to a whole range of people. The answer is information. Some people did some research and started a collectors club... eventually a book was produced. Peces that used to sell for no more than ten pounds fetch hundreds, piece that fetched 50 pounds can now fetch well over one thousand and at list 2 pieces have sold in excess of 5,000 pounds.
It was made part-time, to fill orders, over a period of 30 to 40 years by one team.
At the other extreme Whitefriars bricklayers etc, were hard to sell in the 50p junk box on the pavement outside the shop. Mass produced and now fully documented they even have the added benefit of copies being made to make the collecting more interesting.
So MV is likely to be a full-time production studio/glassworks and lack of information is what hampers it, possibly along with fashion. It takes one person to get interested and arrange their holiday as a research trip.... it could become an important minor maker on the basis of a good article/ book/ website. I doubt it is rare if you take it in the context of similar operations, but due to low information it will be hard to find.