Interesting.
I met a German woman that sculpted in soft glass, she was taught
to work the glass so that it had no strain in it and her pieces never
broke even though she didn't anneal.
Do you use any particular brand of glass ?
Addendum:
After looking at your site I see that Effetre and DH are favorites.
I have a ton of Effetre/Moretti, going to try that black widow today !!
Really incredible work, thanks for sharing.