with about 988 haste rating i have 30.18% haste
throw in 30% from bloodlust/heroism and the fix to spell casting berserking troll racial for another 20% and the t10 set bonus for yet another 20% haste bonus then in theory 30% base+30% BL+20% racial+ 20% 2set= 100% on next spell cast(instant cast) should be able to get about 2 of them off before berserking fades if you pop it right after riptide
is this theory crafting actually possible or is there some sort of hidden cap on haste to prevent instant cast chain heals