Along the way of this journey in discovering the secret to stringer control (aside from the incorrectly perceived tedium of PPP) - I have discovered that in order to really learn, you have to get to know your glasses - intimately!
Not only does finding that sweet spot in flame matter - but how each glass reacts in that sweet spot. There is only one answer for that - try all the types of glasses that you have.
Of course this leads to 'what shall I use this stringer on' - which in itself leads to a whole new lot of experimenting. Because I seemed to be perverse & started with practising my control on small spacer size beads I made a lot of test beads. This in turn forced me to use something to 'pretty' up the base bead when practising with a plainer glass stringer - enter 'frit', which I have previously avoided like the plague, because I have had so little success with it.
"Thai Teal"
I think that has changed! Now I'm enjoying playing with stringer AND playing with frit.