Their inventions could be copied worldwide , they are highschool chemistry with todays standards which does not include complex chemicals , color , heat control. Glass have thousands of years of history and Nash made better than all past examples. Photography have 200 years history and your references neither compete with old examples nor used color , melt or heat. If you read your sent link , you find the recipe extremelly complex and non chemist can not accomplished them with balancing all chemcial knowledge between chemicals.
Nash was one of the most successful glass chemist in england and england was the number on on glass research.
Dont underestimate the art and science , Tiffany was a rich man , everyday drinking champagne and spends half of hour in lab per day , at the mornings. You cant underestimate the craftsmen also. Tiffany have only supplied the money like pope in italy to Michelangelo. If pope visited him , he has no role in sculpture making but a moderate keen eye to art like Tiffany.
All the drawings done by women workers at shop and nobody knows their name today , !!!!