I'm skeptical of the charts. Couple comments:

1. It takes roughly 25s to stack GL3. All attacks after GL3 will have maximum potential DPS. A result of 30-45s is questionable at face value.

2. The length of time that it takes to achieve the DPS or damage target seems to be artificially extended in the second scenario by holding the BFB/IR cooldown until GL stacks are acquired. While this may or may not make sense as a general approach/strategy (I'm actually in favor of using BFB/IR immediately regardless of GL stacks or stacking approach), either way the timing of the external cooldown is artificially skewing the analysis of PB with regards to ramp-up time.

E.g. the longer you wait on big cooldowns, obviously it will take longer to reach maximum DPS. That's a result of when you press BFB, not a result of stacking GL3.

As a result, I recommend removing BFB/IR from the simulation for the comparison.

3. I recommend using some form of rolling window to chart the DPS if possible. The FF14 GCDs are large and the Monk GCDs fluctuate, so this is cumbersome, though. Off the top of my head I can't think of a good method for this. If you're confident in the approach you're taking for measuring/charting the result, then w/e.

Sidenote: after further review, is each datapoint measuring DPS by taking the total damage by that time and dividing by the time elapsed? And, I guess you're marking the average DPS from the full simulation and marking the first point at which your ramp-up hits that DPS threshold? That seems viable enough if so.