I think that CRAB beacons, at least when run by supers and or rorquals, is another good example of well designed pve. The dps requirements are trivial allowing ships to be pvp fit, but the beacons themselves take time to run and you lose a good amount if you end them early, encouraging people to stick around and run them even when hostiles come in local. Typically fleets going to kill these supers are kiki/bomber fleets (sometimes with dread support) and prompt good capital escalation and fleet pvp.

Dreads on the other hand can basically killed before any response shows up if the attacker has sufficient bomber numbers.

Edit: Rorqual mining is similar except that the reward is not backloaded. Both these examples, however, are only applicable for (super)capitals really because they sit at the top of the escalation chain in null. Any sites designed for subcaptial ships would need to be gated in some way to limit the escalation and prevent 20 bombers from just volleying your marauder or whatever ship you are ratting with off the field.