I'm not so sure about Annette Meech - but she was/is primarily an art glass designer.
Where do you draw the line? There are some important studios that produce(d) domestic glassware. It just depends what your criteria are.
Just because it was hand made doesn't mean it wasn't significant.
Cowdy Glass (Pauline Solven) and Lindean Mill (David Kaplan and Annica Sandstrom) spring to mind, among others as producing some outstanding work. However, the entire output of the whole lifespan of those studios is significantly less than what the Arc group produces per hour!
Annette Meech also designed a range of tableware (wine glasses) for Cowdy.
If you are trying to establish who the important designers are, I would advise against using criteria that include either scale of production or method of production and try to judge purely on an aesthetic basis.