Not so long this kinda performance hit was discussed & related to Vampire Survivor case:
https://www.construct.net/en/forum/construct-3/general-discussion-7/c3-good-engine-bullet-hell-170100#forumPost1070610
I saw this post. It's very interesting. And I tested 800 sprites using pathfinding and the prototype didn't lose performance. My problem is avoiding the overlap.
First I tried the behavior "custom movement", but the sprites are "jumping"
Then I tried using the addon "boids", which is very good, but with many sprites, it showed slowness (I don't know if I did something wrong).
Finally, I used your example: dropbox.com/s/4ahybqe3t0k758f/biters.c3p
But enemies would collide and get stuck in each other and "fly" off the screen.
My problem is not performance, I don't know how to prevent sprites from overlapping =(