It's quite the opposite, her skill has very little impact on the burst cap (5% per stack), and is mainly helpful to reaching it, which she can do quite easily since the skill CD is 1T (way easier than Asherat anyways). This is particularly useful when you're holding burst for the right moment, she basically just keeps your team charging up for the best possible burst. Needless to say, she's not really meant in a chain gun bursting team, but rather a nuking one.