British Canopy Technology 1940s/50s

Something has been puzzling me.

Was British canopy technology lagging behind the USA in the late 1940s and early 50s?

Compare the small bubble canopies on a late Spitfire or Typhoon/Tempest with the large glazing on a late P-47 or P-51. When built in Canada the Chipmunk has a large bubble canopy, the British built version was heavily framed. A British Canberra has either a low profile bubble canopy or a slim offset fighter-type bubble whereas a B-57 has a massive canopy. The late Meteor F8 was retro fitted with a metal-reinforced canopy to replace a full bubble type. The Sea Vixen featured a heavily framed narrow canopy for the pilot only.

Was this just a matter of design following a fashion or was there some limitation in plastics technology in the UK at the time?

Any thoughts?