Star guardian invasion (onslaught) velkoz making me lag

Ok I love this game mode and the difficulty makes this even more enjoyable for me. But in some matches, about half way through when we get to the area on the bridge (it looks like its in a park) there are WAYYYYY too many velkoz spawning. Way too many. And I'm not saying this because I can't dodge or its too hard for me, but the amount of velkoz Qs on my screen is making me lag and only at this part. literally goes from perfect fps to unplayable at this part because of the sheer amount of shit on my screen. Is it possible to make less spawn at the same time during this moment of the match??? I basically have to blind land all my abilities and hope my allies kill enough of the velkoz for me to be able to start playing again. its ridiculous.

Edit: I found a workaround. Choose Miss fortune every time and ult a section of the six velkoz and some of my lag is gone right away...