I tried it because another_linux_distro! Sadly, I found the COSMIC dock looks "dead" since they can not implement the genie effect as it is patented by Apple :///////////
I've found that COSMIC heavily rewards navigation via the keyboard rather than via the mouse. Typing super followed by the first few letters of whichever app you want takes a fraction of the time you'd need to pick out the relevant app from a dock.
EDIT: I refer to this effect: https://www.youtube.com/shorts/eOrvbaKz5H4
It is called magnification effect.