It's a great guide but I have some minor suggestions:

For the last leg (r46+) I would suggest making linen shortgloves (1 linen + 1 dew thread) or chef's hats (2 velveteen +1 dew thread). The SP is pretty meh after rank 40, but all that flax starts costing some serious gil and both of those npc decently.

I'd also add Woolen Yarn (fleece x2, natron, distilled water) for around rank 40 or so. Depending on the price of fleece in the wards and the price of flax, wool can actually be cheaper than linen. Both distilled water and natron are available in alchemist's guild. The game is down now, but I believe it's 70 gil for the water and 2178 for the natron.

Also, for r46+ I'd suggest Woolen Cloth (3 woolen yarn) for the last few ranks. At r45, I'm pretty much getting 330 sp for linen cloth and woolen gets me almost 600 sp per synth.

Again, thanks for the great guide!