I see you track cup size using the sfem method, are you still at 8 inches?. To give some context to the sfem method, I've tracked my cup size since September 2012, which was 9.75 (after a year of NBE, post sept. 2013). At present,

it's 14.2 right breast and 13.75 left breast........you have the potential by the looks of things.
When possible, try the XL domes after using the large's, you'll see a big difference. The amount of tissue your pulling looks awesome, nice job. Here's something completely absurd...

it's embarrassing even saying this, I fill the large dome's (to the end).
Isabelle commented on B6 over 40mg turned to T, I've seen some mention of it in research, something to keep in mind. Honestly?, I don't think you need the SP, imo it may be holding you back.