the painting isn't just about colors and flames, we have many elements, but if there is a start position for flames then i believe that it should be the lower left G swirl for many reasons: firstly this is the only G that has fire inside it and the flames to the right (bottom edge) is longer and bigger, whereas on left side edge becomes smaller and fewer even they can't cause any harm to the 2 leafs, notice that we have 2 leafs inside left edge and only one inside top edge, in right edge one leaf just touches the edge, and no leafs inside bottom edge, and we have that queen piece melting as the flames in the bottom edge are stronger.
I thought about that, too. Additionally to your findings inner bottom is the ONLY side where the sequence is in the odd flames. However, using it as starting point yields to not matching sequences at other places.
Have to investigate further
lastly i can clearly see number 2 on the upper edge of the lower right G swirl (after zoom in) which refers to the order of G swirls and direction... ((lower left G is the first then lower right then upper right then upper left))
other than the flames direction i found some letters and numbers, i see 4 or 4A or 42 in the middle of upper edge (its clear even without any zoom)... on the phoenix neck there is a cross and after zoom in you can see 4 or 5 letters BA and YR (inverted) on the cross (maybe it refers to colors) to the right i see Ld and to the left of the cross i see Y2Kc or Y21 (above the red spot)
there is F8 on the Dove's wing which refers to the chess square position (F vertical) + (8 Horizental)
Please take the image and draw your findings into it because I cant see anything of that
Why would OP give a hint after 2 years?