-Warning: Incoming Flush Debaters!-
I flushed and have not flushed and saw a difference and didn't have no crackling, dark grey/black ash.
I saw a difference in a side by side I did and it was obvious to me, others just think It should be getting fatter right now instead of plant detoxing.
It's up to you. You should try it and see.
I will always flush my plants, think about what happens during cure to see what happens during flush. Maybe they don't cure either the non flushers or they like curing to take 4 weeks.