The 2978 (2817 Goblin) is something I would like to try out myself but I am a bit off due to still using a 391 FL Trash staff because Lightning Rod hasn't dropped for me. It would give a much more sustainable DPS due to your total DoT damage increasing and not having to rely on crits as much.
I can understand relying on 10 stacks of stolen time for extra combustion ticks since you can reasonably expect to be at 10 stacks before every combustion, but if you reforged exactly for this cap what percentage of the fight do you think you'd actually benefit from the extra dot tick on pyro and lb?
No, just no, while getting lots of crits in a row will make your ignite stack higher, there is no "secret unknown breakpoint" that causes it. Sure faster fireballs will cause you to possibly get more casts in (therefore more chances at having another crit before ignite drops) but there is no way that stacking haste just for extra chances at stacking ignites is a valid theory.
Weeeeeell, to be fair, it's possible he's talking about the weird Ignite behaviour that was evident on Alysrazor, where an Ignite being refreshed milliseconds before Ignite ticked caused the ticked damage to not be "spent" immediately, so Ignite would ramp up to stupid levels.
But to do that on a regular fight requires phenomenal timing, very good latency, and to be able stand still for a long time. As well as impossible to reach haste levels.
when i changed over to haste stacking i only lost about 4-5% crit and show more consistent numbers pulled 56k on madness 10m without DW was was getting about 400k combusts on average without the 100% dmg debuffs and 700k-1m with 100% dmg. with a little luck you can get good ignites with BL and trinket procs and you can still get good combusts just you wont see them as often. as everyone is sayin though haste will get you more consistent dps but you will have harder time getting the bigger ignites