Here's a few suggestion, although I'm not sure whether this is possible or not.
1. Resetting boss spawn, it's not a spawn hack. More like tricking the game into thinking "We haven't spawn this boss yet, so let's spawn it" after we have kill the boss in the map. Or make the game 'forget' it already spawned a boss. So leaving the map and re-enter it would spawn boss again. Repeat and profit.
2. Endless aggro for quick leveling. Basically more like switching the normal map blocks into Outpost Attack-like aggro.
3. Increase the spawned zombie in 1 map. Let's say the map are limited to 50 zombie only. So increasing it to 100 or even 200 would be a great food for explosive weapon.
4. Increase spawned boss?
Again, I don't know whether any of this are possible or not, I'm just giving a suggestion.