My experience with hydrogen/oxy torches goes back a few decades, but the chemistry hasn't changed in that time. I used them for "glassblowing" fused quartz, which was needed for our work down to 200nm in the UV.I am quite interested in this. Would you be willing to contribute your experience if I were to start a new thread dealing exclusively with torches?
In short, I think it would be absolutely foolish to pre-mix oxygen and hydrogen in any sort of volume and feed that mixture to a torch. We mixed the hydrogen and oxygen before the tip, much like a conventional welding torch, and had flash back arrestors on the H2 line. You still have to be careful, because the combustible limits for H2 are so wide.
John