^^^^ i've spent most of my server playing time now on PVP servers and typically joining 1000+ day servers. as long as the map is 10k sized there's a ton of places to hide out.
only time i've really had a problem was one time i immediately got found by a couple of characters yapping in chinese who immediately homed in on my base because they clearly had all kinds of hacks going on. that was the last time i've played on a server that didn't ban CN.
i would suggest first fixing all the hacks, and then playtest it more.
and right now its nearly impossible to have an above-ground base in PVP so everyone pretty much just digs and hides, then people use xray clipping attacks to find them. bases need to be a bit more defensible so that it takes longer to break into them, and where you can leave a well-built base exposed for 24h and come back and it'll still be there (or you'll hear the auger running and can go hunt down the attackers).
steel bunkers also could be easier to build. right now to build a thick steel block that has no weak points, and which forces attackers to go through X blocks of steel requires sitting around and waiting for layers of reinforced concrete to dry. literally the game has a mechanic of watching paint dry. i sort of understand its to slow down rebuilding a base that is being attacked by zombies during horde night. but the fact that the timer on the blocks doesn't run if there's no active player in the region is pretty annoying. and there's always that one ♥♥♥♥♥♥♥ block that takes forever to dry...
also right now its possible to level up your character and your armor to be able to survive fall damage from 200 blocks and there's tricks like the fact that zombie gore is infinitely soft. so you can summon a horde, have them drop down a pit and die on spikes, then hop on top of the gore and start attacking the spikes (or possibly if there's enough gore just hop across all the spikes and start augering doors and walls).
the fact that zombies hordes are so useful for griefing on servers and that they're unaffected by land claims is also a bigger issue on PVP servers. the goodies from horde night are good, but their use as an offensive weapond is a bit unbalanced.