Work arounds are for devs to solve, not schmucks on lemmy. CS:GO used to use something similar to occlusion culling to prevent this exact problem. Don't send the client all of the enemy locations/data unless the client is within roughly the right distance/sight to see that enemy. This is not a full fix, but dramatically nerfs wall hacking.

I've seen community plugins for TF2 and other source engine games that will add "ghost" players. Generate ai characters, turn them invisible, and send their data to clients. If someone keeps shooting at the ghosts, they can easily get caught and banned.

There are entire industries dedicated to finding solutions to this problem, check out this research paper about this exact subject if you want.