Hello again! I've never had a good high range. Despite having my face on the horn every day (missed less than 10 days a year) for the last 5 years. And regularly (if not everyday) working on range and flexability I've never had anything higher than a

D. After switching from a bach 6 1/2al on my large bore and 6 3/4-ish MP on my small and medium horns to bach 5G's on both, I've noticed my range increase to a (somewhat weak) high E. Sometimes I can even squeak out an F. 2 questions:
1: why might this have happened?
2: after a few months, the 5 has begun to feel small on my face (why I switched in the first place) should I go a size larger? Might I get even better results?
Sorry for the novel, and thanks!